If you live in Sind Province or Baluchistan Province, you should submit following documents to Consulate-General of the People's Republic of China in Karachi: Otherwise, you need to go to the Chinese embassy in Islamabad.

(I) The Original Visa Notice Sheet (JW 101 or JW102 Form) from an authorized governmental organization in China;
(II) Admission Letter from your perspective university;
(III) Secondary School Certificate Examination Marks (original and copy)
(IV) Physical Examination Record for Foreigner (the blank form can be downloaded from this website) attested by the Ministry of Foreign Affairs of Pakistan;
(V) The original passport with validity more than six months and more than 2 blank visa pages;
(VI) One fully completed visa application form in Chinese or English, attached with one of the applicant's recent color photograph (30mm X 40mm).
The back statement is required if the consulater asks for and you can provide your brother's if you list infos of him as your sponsor.