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For further researching the laws of flow resistance, based on the vegetation resistance model under open channel flow, vegetation resistance models were established under six slopes (2°~12°), 〖JP2〗seven flow discharges (3.65L/min, 4.92L/min, 8.13L/min, 11.78L/min, 15.47L/min, 19.12L/min and 27.26L/min) and five vegetation coverage degrees (9.300%，6.975%，4.650%，2.325% and 0) by combined experiment with theory which was adapted to overland flow. Equivalent coverage and equivalent hydraulic radius were defined in the model based on the definition of vegetation coverage and the hydraulic radius in the open channel flow. The results showed that when the other hydraulic conditions were identical, vegetation resistance was increased with the increase of equivalent coverage and equivalent hydraulic radius, the contribution rate of equivalent coverage (0.106) was less than that (0.167) of the open channel flow; however, the contribution rates of equivalent hydraulic radius (0.5) and the drag force coefficient (0.5) were approximately identical with those of the open channel flow (both of values were 0.48), the NSE value of the model was 0.84. This article distinguished vegetation resistance and comprehensive vegetation resistance, which may provide the theoretical basis for calculation of vegetation resistance of overland flow, so as to promote the expansion hydraulics theory of the open channel in the aspect of overland flow.