The flow entering into the Lower Yellow River (LYR) has reduced substantially since 1986 because of the operation of upstream reservoirs, the decrease of rainfall over the catchment and the increase of water demand for agriculture and industry. Accompanying the changes in inflow conditions, the river morphology of the LYR also has some changes. Using the improved Lane's balance equation, the paper gives a quantitative analysis for the channel length (slope), and based on the present problems in the LYR, proposed a new supplementary strategy of river training work to adapt to the changing discharge.