The present disclosure relates to stem cells derived from a pure chorionic trophoblast layer (chorionic trophoblast layer without villi, CT-V), which is a part of the tissues of the placenta, and cell therapy comprising same. Stem cells derived from a pure chorionic trophoblast layer according to the present invention exhibit uniform growth characteristic, and superb proliferation and differentiation characteristics compared to the conventional stem cells derived from the whole placenta, and particularly, exhibit excellent differentiation into cartilage cells, thus can be effectively used in cell therapy for treating cartilage damage, deficiency and such, and as a composition for tissue regeneration.