Aqueous soluble homogeneously alloyed CdSe x Te 1-x (0≤x≤1) semiconductor nanocrystals (NCs) were synthesized by co-reduction of sodium selenite (Na 2 SeO 3 ) and sodium tellurite (Na 2 TeO 3 ) at 120°C under microwave irradiation. The optical modulation of the photoluminescence (PL) between 600 and 710nm could be facilely demonstrated through changing molar ratios of Se to Te. The PL quantum yields (QYs) of CdSe x Te 1-x NCs were lower than that of CdTe NCs. On the other hand, it could be higher than that of CdSe NCs.