It is possible to provide a preventive or a remedy for bedsore which contains an N-acylated derivative of hydroxyproline or its salt, the above-described preventive or remedy which contains from 0.1 to 15% by weight of the N-acylated derivative of hydroxyproline or its salt based on the total weight, and the above-described preventive or remedy for bed sore wherein the acyl group of the N-acylated derivative of hydroxyproline is a C1-24 acyl group.