URGENT: Can I extend my China tourist visa date, before my current one expires?

Hi, my name is Shipra, I'm Indian, working & residing in Hong Kong.
I have traveled to different parts of China many times in past few years.
I have traveled to many countries, and have completely clean travel records.

My current 'multiple entry 6 months validity travel visa' to China PRC expires on 1st Feb 2017.
Can I extend it now in Dec already? Or do I need to wait for 1st Feb for the current one to expire, and then take a new one again. I want to extend right away, from Dec-May 6 month travel entry permit.
I'll be applying for in HK.

Thanks