I am going with family to Korea via Kunming with stop over for 5 hours.

No, you don't have enough time. It takes at least 5 or 6 hours to visit the downtown area, and you need to reach the airport at least 2 hours prior to departure. Thus, the layover should be around 7 to 8 hours.

You are advised to stay inside the airport so as not to miss the flight. Maybe you can have something, or go shopping at the duty-free shops.

As I know, you need to claim your luggage and recheck in on B1, KMG. :)

Thanks a lot Lucy for your reply. So,I have to leave the plan to visit downtown. Regarding baggage claim at KM airport,some one told me that this is required for International to domestic transfer. But for international to international transfer(my case India-KMG-KOREA),no baggage claim or recheck in is required .Can any one please confirm?

If you will travel with the same airline company all the way, you needn't claim your luggage or recheck in. Otherwise, you are advised to confirm this with the airline companies. Good luck! :)