A kit for separating and concentrating body fluid cells is provided. The kit includes a first sealing cap provided with a first close contact body; a first cap connection housing having a first inner connection body in which a first elastic body having a first slit line formed at an end thereof, with which the first close contact body comes into elastic contact when coupled to the first sealing cap, is inserted and disposed in an inner hole so that the first inner connection body is assembled with the first sealing cap; a first housing having one end screw-coupled to the first cap connection housing, and having an inner partition wall formed therein so that a first connection hole corresponding to the inner hole is formed through the inner partition wall; a central housing having one end screw-coupled to the other end of the first housing.