Path compression techniques are efficient on-demand routing optimizing techniques for mobile Ad Hoc networks.This paper analyzed the principles and characteristics of path compression algorithms and proposed dynamic model for the analysis of path compression.This model took the mobility and expansibility of Ad Hoc networks into account and was efficient to analyze or evaluate path compression algorithms.The quantitative relationship and probability expression for pivotal compression events were given based on the model.The simulation results of SHORT and PCA show that it is a correct and efficient dynamic model for path compression.Finally

some suggestions and applications about the model were proposed.