Abstract: It is important to maximize the saturated throughput of 802.11 DCF for fully utilizing wireless bandwidth. The saturated throughput of 802.11 DCF is related to minimum contention windows, maximum backoff stage and the contending nodes in the networks. Based on the analysis to this relationship, this paper induces a simple formula to calculate the optimized minimum contention windows for maximizing the saturated throughput of 802.11 DCF, and gives a self-adaptive contention nodes estimation algorithm, according to which and the simple formula, the optimized minimum contention windows is adapted dynamically. The accuracy of above formula and algorithm is valuated by simulation. The saturated throughput of improved 802.11 DCF and the saturated throughput of 802.11 DCF are compared in this paper. The simulation results prove that the above formula and algorithm are accurate and effective.