My 3-year-old boy has been sleeping late eg 10pm and wakes up as early as 7am. I really wish for him to sleep more to have sufficient rest. Any suggestions to coax him sleep earlier?

If your boy has an afternoon nap, it's time to stop it. Don't go cold turkey, but gradually reduce the time he sleeps in the afternoon. Do some 'winding down' activities before bed time too, like a song, a calming story and even a short back rub :) Good luck!