About fifteen percent of children who wet the bed will mature out of this problem every year, but until he does, here are some steps you can take to try and increase the number of dry nights that he has:
Reassure your child that this is normal at this age and not his fault and understand that he is not doing it on purpose. Also, do not punish or blame your child for wetting the bed and make sure that other family members do not tease him about it.
Avoid letting your child drink large amounts of fluid two hours before bedtime.
Have your child use the toilet just before going to bed.
Protect the bed with a plastic cover between the sheets and mattress.
Let your child help change the wet sheets.
Consider practicing bladder-stretching exercises, in which your child will try and increase the time between urinating during the daytime so that the bladder can learn to stretch and hold more urine at night.
Consider practicing an awakening routine, in which you wake your child to urinate two to three hours after he goes to bed, either at the parent's bedtime or after setting an alarm clock.