Prostaglandin derivatives represented by the general formula (I), pharmaceutically acceptable salts thereof, or hydrates of the salts: (I) wherein X is halogeno of alpha or beta configuration; Y is ethylene, vinylene, or ethynylene; R is C3-10 cycloalkyl which may be substituted with a linear or branched C1-4 alkyl group, or C4-13 cycloalkylalkyl; R is hydrogen or CO2R ; R is hydrogen, linear or branched C1-4 alkyl, or linear or branched C2-4 alkenyl; n is an integer of 1 to 4; and p is 0, 1, or 2.