In this paper,we analyze the scheme of Space-Time Coded BeamForming(STC-BF)for the downlink of DS-CDMA system over frequency-selective fading channels and give the numerical simulations on the scheme.The blind multiuser detection is employed at receiver to suppress the Multi-Access Interference(MAI).The Space-Time Coding(STC)and BF are combined to mitigate the performance degradation due to multipath fading and various interferences.The numerical simulations show that the BF can compensate the performance loss of STC due to the channel correlation and then the STC-BF can greatly improve the performance of CDMA system.