Abstract: Abstract: Plastic ?lm mulching plays an important role in cotton production. However, its widespread use has generate large amounts of plastic film residue and damage the physical structure of soil, which blocks the in?ltration of capillary water and natural water and affects the moisture absorption in soil. Little is known about the impact of film residue on crop evapotranspiration (ETc), and soil evaporation and transpiration. This study aimed to determine the effects of different amount of plastic film residue on ETc using weighable micro-lysimeters (MLS) and water balance methods. A cotton cultivation field experiment was carried out under drip irrigation with plastic film mulching for 2 growing seasons from May to September of 2014 and 2015 in the Tarim Basin, Northwest China (40°06′N, 80°44′E, altitude 1 025 m). Three treatments including plastic film residue amount of 0, 225 and 450 kg/hm2 were designed based on investigation of typical cotton field representing local present situation. Eighteen MLS were buried in soil at 0.15 m depth in each treatment with soil volume of 1424.8 cm3. Soil moisture and evaporation were measured, and ETc, transpiration and ratio of evaporation and ETc were calculated. In addition, leaf area index (LAI) was determined. Resulted showed that the mean evaporation and ratio of evaporation and ETc increased with the increase of residual plastic film amount, which revealed a different trend with the transpiration and ETc. During the whole growing period, residue addition of 225 and 450 kg/hm2 significantly increased the soil evaporation by 6.2% and 14.9% and decreased transpiration by 34.89 and 55.97 mm compared to no film treatment, respectively. The transpiration and ETc were reduced by 3.4% and 4.5% in the entire growing season. Increasing plastic film residue could decrease soil water use efficiency. The increase in soil evaporation in the residual treatment probably is because that the film blocks moisture transportation downward after rainfall and irrigation and the moisture left in surface soil is evaporated. However, soil moisture in no residue treatment could infiltrate to below surface and thus the evaporation was smaller than the residual treatments. Among the 3 treatments, the soil water use efficiency was lowest in the no residue treatment. The relationship between E/Etc partition coefficient and LAI could be described by a power function. The ratio of evaporation and ETc decreased greatly with the increase of LAI in the treatment of 450 kg/hm2 residue. In sum, residual plastic film could change structure of crop water consumption, and this study could provide valuable information for well understanding effects of residual film in soils.