Are Your Kids Sleep Late?

We always have trouble with my son. He always resisting sleeping at night. I start to let him sleep at 8pm but when i put him on bed he will cry and not wanting to sleep. I let him sleep again at 10:30pm still the same thing he will not sleep. Until 12:00 midnight i am worried because we always have trouble about that. I ask the doctor last Friday about that problem and he said it is normal for a kid to resist sleeping at night they just wanting to play. Do you have a problem like this with your kids when they are small? Please do share i appreciated.