Abstract: [Objective] To study the effect of biomass carbon input on soil moisture vertical movement in chloride-sulfate saliferous gray desert soil.[Method]The study materials were gray desert soil in three salinization levels which level 1 was low salinization,level 2 was medium salinization and level 3 was high salinization.Under different percentages of biochar inputs before and through the dropwise add of ddH2O,the time-varying of wetting front and accumulative infiltration capacity were calculated and analyzed.[Result]The vertical migration distance and the cumulative infiltration rate of wetting front were significantly increased(P < 0.05)with the infiltration time of different biomass carbon inputs in each degree of saline soil.The soil moisture movement in level 2 and level 3 saliferous soil were hindered by the biomass carbon;when the input percentage of biomass carbon was less than 4;to level 1 saliferous soil,the soil moisture movement could be facilitated by the biomass carbon;The relationship of biomass carbon input percentage with accumulative infiltration capacity in these three salinization soil were negatively correlated;there was no found in the relationship of biomass carbon inputs percentage with the accumulative infiltration capacity of vertical depth of wetting front in different salinization soil.[Conclusion]The ratio of biomass carbon input,the degree of salinization and the interaction effect of the two have a significant impact on the infiltration efficiency and cumulative infiltration of soil water.The infiltration rate and infiltration amount to moderately saline soil were prominent.Low level input has a promoting effect on water transport in mildly saline soil and inhibitory effect on both cumulative infiltration rate and infiltration rate in severe saline soil.