Abstract: The object was to assess the effect of main quantitative characters of sugarcane on yield. By the method of grey correlative degree analysis, the paper analyzed the correlative degree between main quantitative characters and yield of eleven new sugarcane varieties in 2005—2006. The results showed that the order of the correlative degree of main characters to yield was sugar content per hectare, stalk length, stalk diameter, sprout rate, stalk weight, millable cane, tiller rate. It indicated that sugar content per hectare and stalk length are the main factors which effect the yield of sugarcane. This provided an important theoretic basis for sugarcane breeding.