You need two different visas to China mainland and Hong Kong.
China visa requirements:
(I) Original passport with validity more than six months and minimum 2 blank visa pages;
(II) Photocopy of the first 2 pages (personal information) of the passport and the recent Chinese visa page if there is any;
(II) One fully completed visa application form in Chinese or English, attached with one of the applicant's recent color photograph (30mm X 40mm)
(III) round-way air tickets and hotel reservation.
Pakistani passport holders are exempted from any visa fee when applying for a Chian visa.