To obtain a cloth-softening agent composition having a photo-bleaching effect by compounding a water-soluble phthalocyanine compound and a specific quaternary ammonium compound.

This cloth-softening agent composition contains 0.00001-0.05 wt.% of a water-soluble phthalocyanine compound of Zn, Fe, Ca, Mg, Na, K, Al, Si, P, Ti, Ge, Cr, Ga, Zr, In, Sn or Hr and 1-20 wt.% of a quaternary ammonium compound of formula I [R1 and R2 are each a 1-5C (hydroxy)alkyl; A is a group of formula II or III; B is a 1-5C alkyl, a 8-20C fatty acid or the group of formula II or III; X1 is an anion compatible with the softening agent; (m), (n) and (p) are each a number of 0-51. An aqueous solution containing the softening agent composition is imparted to a cloth and subsequently subjected to a treatment for irradiating light in visible and/or IR regions in the wet state to apply the softening treatment having a good bleaching effect to the cloth.