The soil suffered strong disturbance by the Wenchuan earthquake.It has changed the underlying surface characteristic and influenced the runoff process.The soil infiltration characteristic was the fundamental factor that changed the runoff producing.Longxi River basin in serious Wenchuan Earthquake zone was chose as the study area and double-ring devices was used to conduct the in-situ test.Infiltration characteristics in different types of soils were obtained.The results showed that the saturated stable infiltration rates of different types of soil including forest land

grassland

cultivated land

debris flow fan

landslide land and bare land were 0.32

0.30

0.28

0.19

0.17and 0.07mm/min

respectively.The saturated stable infiltration rate was closely related to the porosity with a correlation coefficient of 0.95.The fine grains and antecedent soil moisture content presented an obvious negative correlation with infiltration rates in debris flow fan

landslide land

bare land

however

they showed no significant influence to forest land

grassland

and cultivated land.Influence of fine grains on infiltration was much weaker than the root system and its rot hole.In addition

soil crust could significantly reduce the soil infiltration.