Abstract: In most existing fair packet sampling algorithms, the sampling probability is usually set according to the estimation of the size of flow which the arriving packet belongs to, so the accuracy of the algorithm depends on the accuracy of the method to estimate the size of the flow and existing algorithms have a high estimation error for mice flow. To solve this problem, a new fair packet sampling algorithm which is based on time sectioning and used to estimate mice flow is proposed according to the characteristic that elephant flow has a high arrival rate and long alive time. The algorithm samples the first packet of every flow in a fixed time section while do not need to estimate the size of the flow. Theoretical analysis and experiments results show that packet sampling for mice flow estimation (MFEPS) method has a higher accuracy and a better scalability at the same CPU resource consumption in estimating the size of mice flow compared with existing sampling algorithms.