In order to investigate the effects of sparse sunlight on the growth, yield, and quality of cucumber in solar greenhouse, the variety of cucumber Cucumis sativus L. cv. Derit L108 is chosen as an experimental material to examine the effects of different shading treatments (1 d, 3 d, 5 d, 7 d, and 9 d) on the growth and fruit quality of cucumber in solar greenhouse during the flowering and fruit set stage. The results are shown below. 1) The plant height and stem diameter of cucumber are significantly influenced by continuous sparse sunlight over 5 d and especially the stem diameter would get thin. The influence of continuous sparse sunlight over 7 d is irreversible. 2) The effects of sparse sunlight on the diameter, growth rate of length, and weight of cucumber fruit are different. The growth trend of the upper and lower diameter of cucumber fruit is more sensitive to sparse sunlight and the effect reaches a significant level in 3 d of continuous sparse sunlight, which is manifested as the growth rate of upper diameter decreasing by 0.87 mm·d-1 and the growth of lower diameter decreasing by a rate between 0.73 mm·d-1 and 0.99 mm·d-1. For the growth trend of the middle diameter and length of cucumber fruit, the effect reaches a significant level by continuous sparse sunlight over 5 d, which is manifested as the growth rate of lower diameter deceasing by 0.88 mm·d-1 and the growth of length decreasing by a rate between 0.87 cm·d-1and 1.00 cm·d-1. Compared with CK (control check), the weight of single cucumber fruit decreases by 18.7 g in 3 d of continuous sparse sunlight, and decreases by a range between 2 g and 3 g for 1 more d of sparse sunlight. 3) The appearance grade of cucumber fruit is greatly affected by sparse sunlight. By continuous sparse sunlight between 1 d and 5 d, the proportion of super class fruit decreases by a range between 9.4% and 43.0%; by continuous sparse sunlight over 5 d, the proportion of second class and bad fruit increases significantly, and the proportion in 9 d of continuous sparse sunlight reaches 20% and 25%, respectively. The difference of water content between the experiment of shading treatment (over 3 d) and CK is significant. The vitamin content is sensitive to sparse sunlight. The vitamin content decreases by about 6% by continuous sparse sunlight between 1 d and 5 d and decreases by a range between 10% and 13% by continuous sparse sunlight over 7 d. The influence of continuous sparse sunlight over 5 d on the content of anthocyanin and organic acid is great. The sensitivity of soluble sugar content to continuous sparse sunlight less than 7 d is low, while the sensitivity to sparse sunlight over 7 d is significant, and the soluble sugar content deceases by 4% for 1 more d of sparse sunlight.