Is masturbation good or bad for male?

Mostly good: Think about the person you love / imagine the person you'll marry. It prepares you for adult roles, makes it possible to focus, won't make you sick or immoral. It's near-universal even among men with partners. Vary your grip / technique -- your experiences with others will vary as well. If you're obsessed with erotica & it interferes with things you need to do, get with your physician.