Abstract: Firstly, for the purpose of studying the integrated effects of many factors on river-bed profile.we considered to put neotectonic movement into the river-bed dynamics model. We got a mathematical model of river-bed dynamics which includes neotectonic movement.Then we studied the effects of different neotectonic movements on river-bed profile and sediment transportation. Some quantitative relations and expressions are studied and gived. For example. the relation between a small quantity of tectonic movement δT and the thickness of deposits δZs. induced by δT’ is that δZs. equals to T. but the signs are differandt Because the change of river-bed profile δZb = δZs +δT= (-δT) +δT=0. δT has no effect on river-bed profile.At last, we distinguished the neotectonic movement at the Lower Yellow River. The neotectonic falling is about 5 mm/a at the Lower Yellow River. Acording to the analysis above. it is clear that the neotectonic movement has no obvious effects on the river-bed profile at the Lower Yellow River, but it has obvious effects on the sediment transportation. There must be an equal quantity of deposits to compensate the neotectonic falling as great as 5mm/a. 

Key words: Neotectonic movement, river-bed profile, river-bed dynamics, mathematical model, the Lower Yellow River