The present invention relates to a fiber product treating agent composition containing (a) a nonionic surfactant containing 1 to 3 polyoxyalkylene groups having the number-average addition mol number of the oxyalkylene group of 50 to 200 and 1 to 3 hydrocarbon groups having 14 to 32 carbon atoms and having an HLB of 16 or more and a melting point of 30 to 80.degree. C., and (b) an amino-modified silicone compound in a mass ratio of the component (a)/the component (b) of 4/1 to 1/4.