PURPOSE: To obtain a liquid detergent composition containing a specific alkali protease, a compound capable of isolating Ca2+ in an aqueous solution and surfactant in specified amounts, having a specified pH, capable of preventing shrinkage of a protein fiber such as wool and having excellent cleansing force.

CONSTITUTION: This detergent composition contains (A) 1-300APU/l alkali protease having optimum pH of ≥9 [preferably alkali protease K-16] derived from Bacillus-sp. KSM-K16 (FERM P3376), (B) 0.001-0.1M compound capable of isolating Ca2+ in an aqueous solution (e.g. CaO or CaCl2) in a concentration of 0.001-0.01M as Ca2+ and (C) 5-60wt.% surfactant (e.g. 10-16C straight-chain alkylbenzene sulfonic acid). The composition has pH ≤9. Furthermore, diglycol Na salt, etc., can be blended as a builder component and the blend amount is preferably ≤3wt.% so as to improve effect for preventing shrinkage of felt of fiber.