High precision,high resolution schemes have significant means in raising the level of the complex supersonic flowfield calculation. WENO schemes are new schemes recently developed which are based on the ENO schemes. The algorithm of weighted factors in WENO schemes was studied and analyzed by theoretic and numeric method. Then, the improvement of algorithm was given. Through applying the improved algorithm to two model problems, it shows that the weighted factor of improved schemes is more smooth. The improve schemes preserve high precision, high resolution characteristics and solve the problem of week oscillatory with varied mesh.