I'm a filipino working in Dammam,Saudi. I want to visit but Dammam has no embassy though

You can entrust a travel agency or someone you know to handle your application from Chinese embassy in Riyadh. Mail application is not acceptable. You can try to contact any of them for help:
Chinese Competitive Spirit Co. for Visa Service
Address: Olaya District, 62nd Street, Sada 1 Business Center, Riyadh
Tel: +966-1-4621258,0501086100
Fax: +966-1-4633850
Office Hours: 08:30-14:00, Saturday-Thursday

Alsandross International Est.
Address: Bin Salem Trading Center, Takhsossi Street, Riyadh (next to the Emirates Airlines Office)
Tel: +966-1-0535363247
Office Hours:
08:30-13:30, 17:00-21:00, Saturday to Wednesday;
08:30-13:30, Thursday