The problem for blind adaptive multi-user to detect the direct-sequence code-division multiple-access (DS/CDMA) signals in multipath fading channels is investigated in this paper. A novel detection algorithm based on constant modulus algorithm (CMA) is proposed. Analysis shows that this algorithm satisfies the decorrelating conditions. This algorithm reduces the complexity remarkably as compared with the traditional SVD subspace algorithm. Simulation results demonstrate that this algorithm offers higher detecting performance and better resistance for both the channel fading and the multiple-access interference.