I'm flying off from Singapore to Seoul and transiting in China

I'm a Filipino working in Singapore and I am flying off to Seoul next week. My itinerary is Singapore to PVG then SHA to Gimpo Airport Korea. I need to trasfer from PVG to SHA, and I would like to ask if do I need a visa to enter China? My stop-over/transit from China to Seoul will be 5 hours in the same day. Do I need a visa for that? Thanks and Regards!