NOTICE OF DOMESTIC SHARE CLASS MEETING

Hong Kong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited take no responsibility for the contents of this notice make no representation as to its accuracy or completeness and expressly disclaim any liability whatsoever for any loss howsoever arising from or in reliance upon the whole or any part of the contents of this notice.Datang Environment Industry Group Co. Ltd.* (A joint stock company incorporated in the People’s Republic of China with limited liability) (Stock Code: 1272) NOTICE OF DOMESTIC SHARE CLASS MEETINGNOTICE IS HEREBY GIVEN that the domestic share class meeting (the “Domestic Share ClassMeeting”) of Datang Environment Industry Group Co. Ltd.* (the “Company”) will be convened at 4:00 p.m. on Friday 28 June 2024 or immediately after the conclusion or adjournment of the 2023 AGM of the Company at No. 120 Zizhuyuan Road Haidian District Beijing the PRC for the purpose of considering and if thought fit passing the following matter (whether amended or not).Terms used in this notice shall have the same meanings as those defined in the circular of the Company dated 29 May 2024 (the “Circular”) unless otherwise specified.Special Resolution (1) To consider and approve the Proposed Amendments to the Articles of Association. The main texts and relevant details of the above resolution are set forth in the Circular which is available on the website of the Stock Exchange (www.hkexnews.hk) and on the website of the Company (www.dteg.com.cn).By order of the Board Datang Environment Industry Group Co. Ltd.* Zhu Liming Chairman Beijing the PRC 29 May 2024 As of the date of this notice the executive Director is Mr. Zhu Liming; the non-executive Directors are Mr. Wang Junqi Mr. Shen Zhen Mr. Wu Daqing Mr. Chen Kan and Mr. Song Yunpeng; and the independent non-executive Directors are Mr. Ye Xiang Mr. Mao Zhuanjian and Mr. Gao Jiaxiang.* For identification purpose only - 1 -Notes: i. The resolution at the Domestic Share Class Meeting will be taken by poll (except where the chairman decides to allow a resolution relating to a procedural or administrative matter to be voted on by a show of hands) pursuant to the Listing Rules. The results of the poll will be published on the websites of the Stock Exchange (www.hkexnews.hk) and the Company (www.dteg.com.cn) after the Domestic Share Class Meeting.ii. In order to ascertain the entitlements of the Shareholders to attend the Domestic Share Class Meeting the register of members of the Company will be closed from Tuesday 25 June 2024 to Friday 28 June 2024 (both days inclusive) during which period no transfer of Shares will be effected. Shareholders whose names appear on the register of members of the Company on Friday 28 June 2024 are entitled to attend and vote at the Domestic Share Class Meeting.To be eligible to attend and vote at the Domestic Share Class Meeting all transfer documents must be lodged with the Company’s board office at No. 120 Zizhuyuan Road Haidian District Beijing the PRC 100097 no later than 4:30 p.m. on Monday 24 June 2024. iii. Each holder of Domestic Shares entitled to attend and vote at the Domestic Share Class Meeting may by completing the form of proxy of the Company appoint one or more proxies to attend and vote at the Domestic Share Class Meeting on its behalf. A proxy need not be a Shareholder. With respect to any holder of Domestic Shares who has appointed more than one proxy the proxy holders may only vote on a poll.iv. The instrument to appoint a proxy shall be signed by the appointer or his attorney duly authorised in writing or in the case of a legal person must be either executed under its common seal or under the hand of its directors or attorney duly authorised.v. To be valid the form of proxy must be lodged with the Company’s board office in the PRC at No. 120 Zizhuyuan Road Haidian District Beijing the PRC 100097 not less than 24 hours prior to the holding of the Domestic Share Class Meeting. If such instrument is signed by another person under a power of attorney or other authorisation documents given by the appointer such power of attorney or other authorisation documents shall be notarised. The notarised power of attorney or other authorisation documents shall together with the instrument appointing the proxy be deposited at the specified place at the time set out in such instrument. Completion and return of the proxy form will not preclude Shareholders from attending and voting in person at the Domestic Share Class Meeting or any adjourned meetings should you so wish.vi. Shareholders shall produce their identity documents and supporting documents in respect of Domestic Shares held when attending the Domestic Share Class Meeting. If corporate Shareholders appoint authorised representative to attend the Domestic Share Class Meeting the authorised representative shall produce his/her identity documents and a notarised certified copy of the relevant authorised documents signed by the Board or other authorised parties of the Shareholders or other notarised certified documents allowed by the Company. Proxies shall produce their identity documents and the proxy forms signed by the Shareholders or their attorney when attending the Domestic Share Class Meeting.vii. The Company has the rights to request a proxy who attends the Domestic Share Class Meeting on behalf of a Shareholder to provide proof of identity.- 2 -viii. Shareholders who intend to attend the Domestic Share Class Meeting shall bear their own transportation and accommodation expenses.ix. In case of joint Shareholders the vote of the most senior one (in person or by proxy) will be accepted to the exclusion of the votes of other joint Shareholders and for this purpose the seniority shall be determined by the order in which the names of such joint Shareholders stand in the register of members of the Company.x. The contact details of the Company’s board office in the PRC are as follows: Address: No. 120 Zizhuyuan Road Haidian District Beijing the PRC 100097 Fax number: +86 10 5838 9860.xi. All dates and time in this notice refer to Hong Kong dates and time.