Abstract: According to the characteristic of data streams，the paper proposes FP-SegCount algorithm for mining frequent itemsets from data streams.The algorithm partitions the data stream and uses modified FP-growth algorithm to mining frequent itemsets in every segment.And then，it counts itemsets in Count Min Sketch.The algorithm solves the problem of compressed statistic and effective computation.Through experimentation and comparision with FP-DS algorithm，FP-SegCount algorithm has a good time efficiency.