New peptide compounds of formula (I) wherein W is a group of formula (a) [in which R1 is hydrogen, halogen, lower alkyl, etc., Q is CH or N, L is a bivalent radical (b) (in which Y is CH or N, Z is NH, O or S, and --- is a single bond or a double bond), etc.,], etc., A1 is lower alkylene, -NHCO-, (c) (in which V is O or S), or -SO¿2?-, T is hydrogen, aryl which may have suitable substituent(s), heterocyclic group, hydroxy, etc., A?2¿ is lower alkylene, R8 is hydrogen or lower alkyl, etc., R3 is hydrogen, aryl which may have suitable substituent(s), hydroxy, protected hydroxy, etc., A3 is bond or lower alkylene, R9 is hydrogen or lower alkyl, etc., and R4 is carboxy, protected carboxy, heterocycliccarbonyl which may have suitable substituent(s), or a group of formula (d) (in which R5 is hydrogen or lower alkyl, and R6 is hydrogen, aryl, ar(lower)alkyl which may have suitable substituent(s), etc.), etc., and a pharmaceutically acceptable salt thereof which are useful as a medicament.