Disclosed is a liver function-protecting agent which comprises a phospholipid as an active ingredient, and which can exhibit an excellent prophylactic and ameliorating effect on the deterioration in the liver function when ingested orally. Also disclosed is a liver function-protecting food, beverage or feed. The phospholipid is preferably one derived from milk or a milk material. Alternatively, the phospholipid may be used in the form of a phospholipid-containing composition prepared from milk or a milk material and containing the phospholipid in an amount of 10 wt% or more relative to the total solid content.