Methane monooxygenase(MMO),an important enzyme in metabolism of methane in methanotrophs, catalyzes the hydroxylation of alkanes and the epoxidation of alkenes. In addition,MMO can biodegrade haloakanes and haloalkenes. Being one of the proteins containing binuclear iron centers,MMO can activate oxygen for insertion into a C-H bond.The elucidation of structures of active centers of MMO is significant for methane utilization and design of chemical catalysts. This article will concentrate on progress on above researches.