With cucumber varieties ‘Jinyou No.4’ and peanut vine straw,corn straw and rice husk of after 1 year rotten as test materials,the effects of different crops straw returning on growth and photosynthesis characteristic of cucumber were investigated in protected cultivation.The results showed that:(1)Crop straw returning not only could significantly increase root activity and leaf nitrate reductase activity of cucumber,but also could improve leaf chlorophyll content,F^v/F^m,Ф^PSⅡ and photosynthetic rate of cucumber leaves,compared with the control.So light use efficiency of cucumber leaves was increased,net photosynthetic rate significantly enhanced,thereby promoting growth and development of cucumber.(2)The plant height and stem increased,the fresh and dry weight of cucumber increased,and significantly improved the yield of cucumber.(3)One of the best straw returning is maize straw returning,its yield reached 5 765.74 g·m^-2,the treatment yields 43.8% higher than compared with the control;followed by peanut vine straw returning,rice husk straw returning less effective.We concluded that straw returning promoted root absorption capacity,significantly improved leaf nitrogen metabolism,light energy use efficiency,net photosynthetic rate of cucumber,so as to promote the growth of the cucumber plant,improve the production,and the effect of corn straw returning was the best.