Taking tomato variety‘ bofen’ as experimental material and ordinary film as the contrast，this paper studied the effect of diffuse light thin film on tomato growth and fruit quality. The results showed that tomato had strong growth vigor under diffuse light thin film，the content of chlorophyll was higher，the fruit
setting number and average single fruit weight were increased by 12.52% and 7.71%，respectively. Its yield was also promoted by 21.19%. Besides，the fruit volume was significantly enlarged. The fruit shape index was 0.8-0.9. Further more，its fruit quality was improved. The contents of soluble solid content and VC were remarkably increased，indicating the diffuse light thin film was not only helpful for promoting tomato plant growth，but also for improving its fruit quality.