You'd better apply in Syria. The requirements are as follows:
1. Passport valid for more than 6 months with enouth blank visa pages.
2. Application form for China (both V2011A and V2011B) with photo stuck to it.
3. An Employment License of the People's Republic of China for Foreigners (which could be obtained by the employer in China from the provincial or municipal labor authorities) and a visa notification letter/telegram issued by an authorized organization or company are required. Moreocer, your previous China visas and copies are also needed.
Your wife and children are also required an original Visa Notification/invitation letter issued by the Chinese Ministry of Foreign Affairs and Proof of relationship - original NSO birth certificate or marriage contract.