Since the river closure of main channel of the Three Gorges Project (TGP)in 1997, the temporary lock has been operating smoothly, and it has experienced hydrologic year with abundance of water and sediment in 1998 and year with abundance of water but low sediment in 1999. Through the field observations and real ship tests, the data were collected about sediment accumulation, velocity and pattern of flow in the approach channel. Comparison between prototype observed data and model test results shows that the latter are basically reasonable, and some predicated values approximate to the former. These results have provided important basis for the design and operation of permanent navigation structures.