Hydroxycitric acid derivatives and salts thereof are provided which are useful as active ingredients of skin external preparations and cosmetics. Also provided are processes for production of the hydroxycitric acid derivatives, and skin external preparations and cosmetics containing the hydroxycitric acid derivatives. Specific hydroxycitric acid derivatives or salts thereof are produced wherein at least one of the hydroxyl groups of hydroxycitric acid or least one of the hydroxyl groups and at least one carboxyl group of hydroxycitric acid are modified to linkage moieties breakable by biological enzyme reaction. The hydroxycitric acid derivatives or salts thereof are added in skin external preparations and cosmetics.