AlGaInP:Si/GaInP:Si and AlGaInP/GaInP multiple quantum well structures were grown by low pressure metalorganic chemical vapor deposition. The effect of Si-doping on the characteristics of AlGalnP/GalnP multiple quantum wells was studied by using double crystal X-ray diffraction and photoluminescence. The results show that the growth rate of MQW increases with Si-doping and the intensity from MQW with Si-doped was approximately one order pf magnitude stronger than that of undoped MQW.