There are few related studies on the evolution mechanism of water conservation function driven by landscape pattern in karst areas,and water conservation function is one of the key indicators of ecological benefits of ecological restoration projects such as the central of karst rocky desertification,which has important research significance.Taking the Yeji River Basin located in the center of the Southwest Karst as the research object,based on the InVEST model,partial least squares model (PLSR),landscape ecology theory,etc.,this paper explored the spatial and temporal variation of water conservation function and its coupling relationship with landscape pattern in the Yeji River Basin from 2005 to 2020.The results showed that:(1) The landscape types of the Yeji River Basin were mainly dryland,grassland and shrubbery,and the mutual transformation between each type is relatively frequent.The general characteristics were the conversion among dryland,shrubbery and grassland and the squeezing of construction land on other land types.(2) During the study period,dryland landscape tended to be fragmented,the construction land showed an agglomerative expansion trend,and other landscape types were relatively stable.In general,the landscape pattern showed a fragmented development trend,and the landscape connectivity showed a slight upward trend.(3) The interannual variation of water conservation in the study area showed a continuous growth trend,and the spatial distribution showed a trend of low in the middle and high in the north and south.The order of water conservation depth from high to low was shrub forest > forest land > sparse forest land > grassland > dryland > construction land > paddy fields > lakes > reservoirs and ponds.(4) The increase of landscape fragmentation and the improvement of patch quality could improve the water conservation function of karst basins,but the excessive degree of landscape fragmentation may lead to the decline of water conservation function.In general,during the study period,the landscape pattern of the Yeji River Basin showed a trend of fragmented development,and the water conservation function showed a continuous increasing trend.The impact of landscape pattern on the water conservation function was complex.The research results can provide important scientific basis for landscape planning and water resources protection in karst watershed.