We'll visit Bejing on May 12 to 19, 2012. What kind of clothes must we bring to?

The average temperature is about 14~26C during May in Beijing. It won't have much rain at that time. You can wear long-sleeved T-shirts and Jeans. Well, better bring a light jacket. Some people will wear short leeve T shirt but a light jacket at night and early morning is necessary.