Abstract: The paper focused on the effect of different additive amount of 0,30,40,50,60 and 70 g of cassava flour on the gelatinization characteristics,fermenting power of wheat flour and aspect ratio,specific volume,textural properties and sensory score of steamed bread.The results showed that with increase of the cassava flour,the peak viscosity,valley viscosity and breakdown value of composite flour increased. The find visa viscosity and set back value were first decreased then increased. The gelatinization temperature and peak time decreased. The maximum height and final fermentation height of dough decreased and the fermentation time of dough extension. The aspect ratio and specific volume of steamed bread decreased and the hardness and chewiness of steam bread increased. The sensory score results showed that there was no significantly difference between the steam bread of adding amount of cassava within 40 g and the control group(P>0.05). It could conclude that the optimal adding amount of cassava was 40 g.The effect of gluten on quality improvement of 60 and 70 g high proportion cassava flour steamed bread was aslo studied. The results showed that high ratio and specific volume of high proportion cassava steam bread increased significantly(P<0.05)and the hardness and chewiness decreased significantly(P<0.05)by adding 6% of gluten with a sensory score of 70.86 and 70.18 points respectively. The quality of high proportion cassava steam bread was almost like the quality of addition amount of 40~50 g of cassava steamed bread.