I am Indian national working in singapore, i would like to visit my friend in Guangdong China,

Ashif, you can apply for a tourist L type for that. You should first prepare those documents your work permit in Singapore, the application form, a passport-style photo, your passport and copy of its data page, and an invitation letter from your friend. Next, go to the CVASC to submit your application. How long the validity will be depends on how long you need; the consular officers will give you proper validity based on your travel itinerary.

Thanks Fiona for your valuable reply!!