Skin improving substance regulating cadherin 11 or n-cadherin expression, and method for screening for same

The present invention can alleviate skin hyperpigmentation and can provide skin whitening effects by providing: a composition for skin improvement, containing, as an active ingredient, a substance inhibiting the expression of cadherin 11 and/or N-cadherin; and a skin improving kit including the same. In addition, the present invention can effectively screen for a skin improving substance by providing a system for screening for a skin improving substance containing a coculture product of at least two among fibroblasts, keratinocytes and melanocytes, and a method for screening for a skin improving substance, comprising the steps of: treating, with a candidate substance, a coculture product of the system for screening for a skin improving substance; and measuring the expression change in cadherin 11 and/or N-cadherin.