Do you mean "you belong with me"? In this case she is saying they should be together, or they are destined for each other. "You belong to me" would be more like " i own you", you have to do what I say.

"Belong with me" should be taken in the context of the other lyrics of the song. In the said song, the singer states that she's the only one who can understand the object of her affection, and on that basis, the former "belongs" to her. So in this context, "belong" means "compatible". Although there better synonyms to "compatible" in English, "belong" sounds better.

CAN I HELP YOUR CHINESE?