Chief Executive Carrie Lam will visit Shanghai and Hangzhou from August 22 to 23.
In Shanghai, Mrs Lam will deliver an address at a gala banquet to celebrate the Hong Kong Special Administrative Region’s 20th anniversary and will meet with municipal government officials.
She will then go to Hangzhou for a meeting with Zhejiang Province leaders.
Mrs Lam will be accompanied by Secretary for Constitutional & Mainland Affairs Patrick Nip and the Chief Executive's Office Director Chan Kwok-ki.
Chief Secretary Matthew Cheung will be Acting Chief Executive during Mrs Lam's absence.
Under Secretary for Constitutional & Mainland Affairs Andy Chan will be Acting Secretary in the absence of Mr Nip.