Abstract: For the problem that the low efficiency of time constrained sequential pattern mining algorithm in the aspect of time and space, this paper proposes trajectory sequential pattern mining with the relative time. The algorithm uses the relative time as a constraint condition.Firstly,it computes grid density of the relative time based on grid division,and then obtains regions of interest through extension dense grid.What is more,conduct trajectory sequential pattern mining on the basis of regions of interest.Experiments on real dataset show that this algorithm maintains better efficiency in time and space performance than traditional sequential pattern mining algorithms.