The direct current and microwave modul ation characteristics of vertical cavity surface emitting laser (VCSEL) with bla zed grating as external cavity feedback is studied experimentally.The Fabry-Pero t(FP) cavity is composed of the bottom plane of VCSEL and the external grating and microwave modulation efficiency can be enhanced because of the feedback eff ect of the grating.When the VCSEL is driven only by direct current,the sideband power whose frequency related to the length of the FP cavity is observed.When th e length of the FP cavity is adjusted to couple with microwave modulation freque ncy,two times of effective sideband power can be obtained under the same microwa ve power.The results show that grating external cavity VCSEL can obtain more eff ective sideband power over a wider range of input smaller microwave power.The st udy will provide some reference for microwave modulation VCSEL and other semicon ductor laser applications.