Some times after masturbation my penis start burning from tip . and urin come in 1 or 2 drops and i goes on for half or an hour plz tell me why ?????

Without a complete physical, medical history, and family history, there is no way to know that is going on. It could be an STD, or sphincter weakness, or prostrate problem, or kidney problem, or a hundred other things. It is something you should talk to your doctor about. Don't be embarrassed, the chances are that he's had to deal with worse.