Abstract: Ecosystem services are natural environmental conditions and functions provided by ecosystems and their ecological processes． Quantitative evaluation of ecosystem services is an important prerequisite for sustainable ecological resources． The spatial heterogeneity of ecosystem services and influencing factors in different forest types (conifers, broadleaves and mixed forest) in Beijing were analyzed with GeoDetector． Net primary production (NPP) of coniferous forest (324.08 g·m⁻²·a⁻¹) was found to be greater than broad-leaved forest (303.33 g·m⁻²·a⁻¹) and mixed forest (291.74 g·m⁻²·a⁻¹)． Environmental improvement services were largest for coniferous forest (251.91 kg·a⁻¹), followed by mixed forest (215.39 kg·a⁻¹) and broad-leaved forest (155.36 kg·a⁻¹), while both production service and soil and water conservation service were the largest for broadleaf forest． The main drivers of spatial heterogeneity of ecosystem services in different forest types were found to be meteorological factors． The main drivers of water production and environmental improvement were precipitation and temperature． The main drivers of NPP were temperature, precipitation and radiation． A synergistic relationship was found to exist between water production service, NPP and soil and water conservation: the larger the water production service, the larger the value of NPP and soil and water conservation． Interaction detection showed that most factors, such as elevation and climate factors, interacted with each other; therefore spatial heterogeneity of various ecosystem services was strengthened． When afforestation is carried out for the purpose of a certain ecological service, attention should be paid to measures such as irrigation, moisture preservation and heat preservation, influence of topographic factors should be considered． The interaction of different impact factors should be fully considered when analyzing the ecosystem service function of plantation．