You can apply for China tourist visa at the Consulate General of China in Dubai, the requirements for China tourist visa are:
1. Original passport with blank visa pages and validity of more than 6 months;

2. UAE resident visa valid for more than 6 months. (Excluding non-GCC applicants);

3. Application Form which must be completed neatly and signed by the applicant;

4. One passport photo (and the photos of the applicant's accompanying persons included in his/her passport if they plan to travel with the applicant.);

5. Copies of the data pages of the applicant's passport and UAE resident visa.

6. A No-objection letter from the applicant's company stating his or her position ,monthly or yearly salary;

For Hong Kong visa application, you should mail the application to
Hong Kong Immigration Department, Employment and Visit Visas Section,
24/F Immigration Tower, 7 Gloucester Road, Wanchai Hong Kong.
You can refer to http://ae.china-embassy.org/eng/lsyw/1/2/t630669.htm to get more information about Hong Kong visa application.