Abstract: In this paper,a novel method is presented for the rapid synthesis of glutathione（GSH）-capped ZnSe nanocrystals in aqueous phase assisted with microwave irradiation.The as-prepared ZnSe nanocrystals have tunable fluorescence emissions between 360 and 410 nm with narrow full width at half maximum（FWHM）of 21 nm.Moreover,the luminescent properties were greatly improved through photochemical treatment.Their photoluminescence quantum yields（PLQY） reached as high as 55% after illumination.The key synthesis parameters（molar ratio of reagents,pH values,reaction temperature,and time） are fully discussed.The facile synthesis of glutathione-capped ZnSe nanocrystals is free of complicated manipulations and cost-effective.Furthermore,the water-dispersed ZnSe nanocrystals with high luminescence and favorable biocompatibility allow their potential applications in biological imaging as fluorescent labels.