Why he hits Babies this age usually strike out when they are frustrated or don't have the words to express what they want or need. If he's socking another child because he wants a toy she has, he may need you to act on his behalf. But you can't let your toddler think that any of these outbursts, including pushing, biting, and hair grabbing, are acceptable behaviors.
What you can do When your child has a meltdown, quickly and quietly remove him from the situation. If you get agitated, that may actually make him do it more often. Make your response simple and brief. Say: "That is not okay. Don't hit." If you spank a child who hits, your words contradict your actions. Offering your child positive reinforcement will also go a long way toward putting a stop to his baby beatdowns. If you see him playing nicely and sharing, encourage him to continue and show him that you are happy and proud of his actions.