The invention provides Hubei polysaccharide in ophiopogon japonicus for treating type II diabetes and a method for preparing the same. The Hubei ophiopogon japonicus is a trueborn crude drug and unique species from Hubei province, and the root of the Hubei ophiopogon japonicus can be used for pharmaceutical purpose. Tests prove that the Hubei polysaccharide in ophiopogon japonicus has effects of lowering insulin resistance and obviously reducing blood sugar, and can obviously improve the sugar tolerance of the type II diabetes. The Hubei polysaccharide in ophiopogon japonicus for pharmaceutical purpose for treating the type II diabetes has the characteristics of obvious treatment effect, no generation of toxic and side effects, easy acceptance by patients, the suitability for long-term control of the disease and the like.