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Film mulching can change radiation transfer, increase soil temperature, reduce soil evaporation and so on. Potato has good nutritional value and produce more dietary energy than rice, maize and wheat. Potato has shallow roots and is sensitive to hydrothermal conditions. Field hydrothermal environment can be regulated through the combination of film mulching and drip irrigation. Drip irrigation with film mulching can increase potato yield and water use efficiency and improve potato quality. Optical properties of film are important factors affecting field thermal conditions and potato growth. The effects of film mulching on field thermal conditions and potato growth are also different in different regions with different climatic conditions. The experiments were conducted in Gansu Province from April to August 2015 and Shandong Province from March to July 2017, respectively. Effects of different film mulching (clear film, CF; no film, NF; black film, BF) on heat conditions and potato growth under drip irrigation were studied. Canopy net radiation, soil heat flux and soil temperature were monitored automatically during the whole growth period. Potato yield, tuber grade, water consumption and water use efficiency were measured. The results suggested that net radiation of BF treatment was greater than that of NF and CF treatments, while net radiation of CF treatment might be higher or lower than that of NF treatment. The maximum net radiation of BF treatment was 12% greater than that of NF treatment during sprout development stage and seedling stage in 2015 and 22% and 15% greater than that of NF treatment in 2017, respectively. The differences of soil heat flux and soil temperature between treatments were great during sprout development stage and seedling stage, decreased during tuber initiation stage and tuber bulking stage, and increased during maturity stage. The maximum soil heat flux at 10cm soil depth of CF treatment was 66% and 129% greater than that of BF and NF treatments in 2015, respectively, and it was 57% and 91% greater than that of BF and NF treatments in 2017, respectively. The soil temperature of CF treatment was greater than that of BF and NF treatments, while it might be lower than that of BF and NF treatments during tuber initiation stage and tuber bulking stage. In 2015, the daily maximum soil temperatures at 10~50cm soil depths of CF treatment were 29% greater than that of BF treatment, and 31% and 29% higher than that of NF treatment during sprout development stage and seedling stage, respectively. In 2017, the daily maximum temperatures at 10~50cm soil depths of CF treatment were 22% and 4% greater than that of BF treatment, and 21% and 9% greater than that of NF treatment during sprout development stage and seedling stage, respectively. The difference of soil temperature among different treatments in Shandong Province in 2017 was smaller than that in Gansu Province in 2015. Film mulching significantly improved potato yield and water use efficiency in Gansu Province and the evapotranspiration of CF treatment was significantly lower than that of BF treatment. However, film mulching did not significantly improve potato yield and water use efficiency in Shandong Province in 2017. The evapotranspiration of CF treatment was lower than that of BF treatment in Gansu Province. The effects of film mulching on thermal conditions and potato yield and water use efficiency were more remarkable in Gansu Province than that in Shandong Province. Clear film mulching was favorable for potato cultivation in Gansu Province. 