Abstract: This paper gives some verification results of the fluvial formula for macro-tide estuary with tidal bore. In general, the average cross-section area of an estuary can be calculated by the average ebb tide discharge (including runoff discharge) and the average ebb sediment concentration. The formula is widely used for estuaries and bays. However, as the width and depth of macro-tide estuary with tidal bore is wider and shallower than general estuaries, using coefficient of tidal bore is not enough to offset the inaccuracy. Instead, when using the flood tide discharge and flood sediment concentration, the results are in good agreement with field data. By using the flood and ebb tide discharge distribution around the cross-section, it easily explains the reasons for reduced errors. This paper also gives the definition and calculation formula of the enlargement ratio of width and the enlargement ratio of cross-section area based on the 50-year and 130km long distance field data observed before and after the regulation of the Qiantang estuary. The paper verifies the relationship among the characteristics of cross-section, the enlargement ratio of width, the enlargement ratio of cross-section area and the characteristics of river curves.