The raising of river profile can be regarded as a stochastic process.The parallel raising of river profile means that the trend in the process is parallel.Whether the profile raising is parallel or not should be decided according to its trend raising and should not be judged according to its total or random raising,MA(moved average)model can be used to obtain the information of the trend raisong of the river profile.If the raising of profile is parallel,there will be following situations:1.The difference of water levels between two sites along the profile should be a constantu;2.The mean value of the annual raising of water levels at all sites along the profile should be equal.All these propositions are examinated by using statistical test methods(stutend test).Such conclution is obtained that the trend raising of the profile of the lower reach Yellow River is parallel(from Huayuankou to Lijin).