I assume you mean "one of a kind" rather than "one kind of"?
If so, they mean the same thing. Something that is unique is the only thing of its kind (type/classification); there are no others like it. It is one of a kind.
- This rare vase is one of a kind, there are no others like it, it is unique.
- She is one of a kind, we will never find another manager like her. She had a unique set of skills.