Abstract: Six sugarcane varieties, GT11, ROC16, B1, B3, B5 and B8, were grown in the barrels without nitrogen fertilization. The indexes in relation to photosynthesis were investigated. The four nitrogen fixing varieties B1, B3, B3 and B8 were more efficient in photosynthesis with higher net photosynthetic rate, activity of ATPase and chlorophyll content. No nitrogen-fertilization negatively affected the photosynthesis of GT11 and ROC16. The variety B8 showed the highest photosynthetic ability while the variety GT11 the lowest, and the photosynthesis of the latter was more sensitive to lack of nitrogen.