The performance of backoff algorithm plays an important role in designing efficient Medium Access Protocols for Ad hoc networks. In this paper, we propose three backoff algorithms for Ad hoc networks. The first algorithm aims at higher fairness, and the second aims at stronger adaptivity. Then, we combine the first two algorithms to propose an optimized backoff algorithm. We use NS2 to simulate Ad hoc network environment to evaluate the performance of our improved backoff algorithms. The results show that our algorithms exhibit a signiﬁcant improvement in throughput and fairness with the existing BEB and AASC algorithm.