Is it good to go to Beijing in March. Can I go Great Wall in March

Hi, generally yes, but it will still be cold, with the average temperature of 6-7C. Temperature may fall a lot from daytime to night. Thus keeping warm comes first.

Anyway, flowers begin to bloom and trees start to bud, so it can be a nice time for mountain climbing and enjoying the local plants. Of course, Great Wall visit then would also be a nice choice.