i'm thinking of to visit beijing on 10december to 16 december.. How about the weather?

Well, it will be during winter of the city, with the average temperature of about 0C. It would be dry and chilly. I suggest you take along down jacket, sweater and Long John. You'd better pay attention to the weather forecast and sometimes scarf and gloves are also needed. In addition, it might snow at that time according to the past weather records.