Disclosed is a fat accumulation inhibitor for a fat cell, which comprises a milk-derived phospholipid as an active ingredient, wherein a milk derived phospholipid-containing composition is used as the milk derived phospholipid, in which the milk-derived phospholipid containing composition is prepared from a milk or milk material selected from a butter serum or a butter milk and comprises a lipid in an amount of from 20 to 90% by mass based on the total solid and a phospholipid in an amount of from 40 to 55% by mass based on the total lipid, wherein the milk-derived phospholipid-containing composition is obtained by adjusting the milk or milk material to pH of 4.0 to 5.0 by adding an acid, thereby removing a casein protein as a precipitate, and then treating with a microfiltration (MF) membrane having a pore size of from 0.1 to 2.0 microns or with an ultrafiltration (UF) membrane having a fractionating molecular weight of from 5 to 500 kDa.
