Based on the importance sampling (IS), this paper proposes a new algorithm to estimate the time delay and amplitude in multipath channels. This algorithm decouples the time delay and amplitude estimation and utilizes Monte Carlo method for sampling unknown parameters. By so doing the parameters are approximated by the average of samples, and the estimator proposed in this paper avoids the complex multidimensional grid search and iterative methods which depend seriously on the initial guess. The results show that the algorithm performs well under condition of respective multipaths 5, 15. Compared with some other known algorithms under the same condition, the algorithm can achieve not only the time delay estimation, but also a precision amplitude estimation simultaneously.