Based on the investigation to farm households in Yujiang County, J iangxi Province, the mechanism of farm household’s soil and water conservation investment behavior ( FHWSCIB) is analyzed. The factors which mostly influence the FHWSCIB are the multi-operation behavior of farm household, habit of manufacture, the scale management of agricultural land, the status of agricultural labor, soil and water loss disaster and economic condition of a family. In order to analyze the relativity between the FHWSCIB and these indeice, a multi2linear regression model is established. It turns out that the FHWSCIB is mostly influenced by the proportion of non-agriculture income, the time spent on farm, agriculture population, area under cultivation, soil and water loss disaster, average income and the distance f rom county to city. Farm households who have a great proportion of non-agriculture income have a less enthusiasm for soil and water conservation investment,while those who have more agricultural labors or whose members are more indust rious have more soil and water conservation input s. At last, some pieces of advice are presented on how to prompt the FHWSCIB and improve the status of soil and water loss.