When the multiple-access interference (MAI) in DS-CDMA system is very strong, the performance of adaptive blind multiuser detection in the system will degrade significantly. The normal way of solving this problem is increasing the length of spreading code. However, the improvement is limited. This study proposed a novel blind multiuser detection scheme with Kronecker spreading code, which is generated by the kronecker product of normal spreading code. Theoretical analysis and simulation show that the Kronecker spreading code has much more capability of resisting MAI than the normal spreading code, which has the same length of the Kronecker spreading code. Therefore, the Kronecker spreading code performs much better in the adaptive blind multiuser detection.