The temporal and spatial variations of groundwater depth and normalized difference vegetation index(NDVI)in the lower reaches of the Tarim River in summer before and after water transmission were analyzed by using empirical statistical model and Kriging interpolation method, taking the 12th to 18th ecological water transmission in Tarim River as an example. The cumulative ecological response law of groundwater and vegetation to ecological water transmission was analyzed. The results show that the cumulative water transmission is positively correlated with the minimum groundwater depth, and the cumulative effect increases from strong to weak. The response of groundwater depth to the cumulative time of ecological water transmission is lagged, and the cumulative effect is most significant after 80 days of water transmission. Along the river course, the cumulative spatial effect of Kurgan monitoring section is the most significant. In vertical channel direction, the spatial response of groundwater to cumulative water transmission decreases with the increase of channel distance. NDVI was positively correlated with the amount of cumulative water transmission in the past three years, and increased significantly near the Daxihaizi Reservoir, Taitema Lake and river channel. It is recommended that the recent water transmission range from 250 million m³ to 500 million m³ each time, the reasonable water transmission time should be in the month of April to June and Seplemper to November, and the suitable water transmission interval should be 5-12 months. It is estimated that the cumulative effect after five consecutive water transmissions can reach the minimum groundwater depth of 3. 5 m and the average groundwater depth of 4. 2 m.