[Objective] Soil and water conservation and ecological benefits of forest ecosystem in the new urban karst areas of Guanshanhu District, Guiyang City in Central Guizhou Province were studied to scientifically evaluate the achievements of ecological construction, and to provide a scientific reference for the sustainable utilization of resources and the environment, and high-quality development of forests in new urban karst areas.[Methods] The distribution patterns of forest ecosystems at Guanshanhu District at 2000, 2010, and 2020 were extracted by using multi-source remote sensing data. The soil conservation and regulating water amount were calculated by a soil conservation model and the water balance equation. The ecological benefit value was calculated using the market value method and the shadow engineering method.[Results] ① The area of the forest ecosystem at Guanshanhu District increased from 10 892.74 hm² to 15 571.90 hm² during 2000-2010. Forest area decreased with the acceleration of urban expansion, and was 13 937.54 hm² by 2020. Due to the opposing influences of ecological engineering and urban expansion, the forest ecosystem has changed greatly during the past 20 years. ② The value of soil and fertilizer conservation and water regulation in the forest ecosystem generally showed an increasing trend, and the ecological benefits per unit area increased. However, due to the decrease in forest ecosystem area, the ecological benefits of soil and fertilizer conservation and water regulation increased slowly. ③ Soil conservation per unit area followed the order of coniferous forest>mixed coniferous and broad-leaved forest>shrub forest>broad-leaved forest>other forest. The regulated water amount followed the order of coniferous forest>broad-leaved forest>mixed coniferous and broad-leaved forest>shrub forest>other forest. The total value of the ecological benefits of soil fertility and water regulation in coniferous forest was the largest, followed by shrub forest. Shrub forest played a very important role in soil fertility and water regulation.[Conclusion] The forest ecosystem changed greatly at Guanshanhu District, and the area increased significantly from 2000 to 2010, but exhibited a decreasing trend in recent years. However, the per unit area ecological benefits increased continuously, and played an important role in soil and fertilizer conservation and water regulation. Forest ecosystem protection should be given great importance in the development of new urban areas.