The man was arrested by police after he was reported by his mother for beating his younger sister on Thursday night.
The 16 year old girl sustained a broken left arm and a dislocated shoulder from the beating.
Police said the man beat his sister because she refused to give him money for alcohol.
The incident took place at their 3 mile house in Port Moresby.
The man is now in custody and will be facing charges of assault and using threatening and intimidating words.