Objective:To discuss the feasibility of the viscosity determination method in the registration standard of type IB magnesium aluminum silicate.Methods:Two different types of high speed blender and rotary viscometer were used to investigate the viscosity of IB-type magnesium aluminum silicate.Results:When the viscosity of mag-nesium aluminum silicate(IB type)was investigated by rod high-speed stirrer and rotary viscometer,the samples did not meet the requirements.When the viscosity of magnesium aluminum silicate(IB type)was investigated by wall breaker and rotary viscometer,the samples met the requirements.Conclusion:IB type magnesium aluminum silicate is a thixotropic non-newtonian fluid,and the viscosity measurement results of it are greatly affected by the high speed blender.It is recommended that the type of high speed blender which is suitable for use in the test should be specified.