Using regular brown rice, red rice and black rice as raw material, the radial expansion rate, water soluble index, water absorption index, dispersion time, agglomerate rate,paste viscosity, gelatinization degree, reducing sugar and protein contents of brown rice flour produced by thermostable α-amylase assisted extrusion treatment was measured. The results showed that after thermostable α-amylase assisted extrusion treatment, the radial expansion rate and gelatinization degree in three types of whole brown rice were reduced significantly(P<0.05). The water soluble index was increased(P<0.05) by 2.51 times, 1.89 times and 2.73 times, respectively. And the water absorbent index was decreased significantly(P<0.05) by 77.29%, 33.41% and 67.44%.The dispersion time and agglomeration rate were also reduced significantly(P<0.05). The dispersion time was reduced by 64.60%, 60.66% and 65.40%, respectively. The agglomeration rate was reduced by 75.57%, 84.64% and 75.24%. The dissoving viscosity decreased significantly(P<0.05). The whole brown rice flour treated with enzyme had lower viscosity at low shear rate, and its viscosity curve tended to be straight. The content of reducing sugar and soluble protein was increased significantly(P<0.05), while the content of total protein had on obvious change(P>0.05).