The stability of pesticide SC suspension was studied by Turbiscan Lab Analyzer. The Turbiscan Lab can be used to analyze the concentrated colloids, dispersant samples, and the instable mechanism of the suspension system in the initial stage. The Turbiscan Lab can also determine the thickness changes of sedimentation with the time, the settling rate of particles with time, and the particle size changes with time. In the present work, the different dispersant GY-D10, NNO, Morwet D-425, TERSPERSE 2425 were used to prepare the imidacloprid 350 g·L-1 suspension concentrate in the same preparation condition. By measuring the light intensity of backscattering light of the suspension of imidacloprid 350 g·L-1 SC with time, the dynamic sedimentation processes and the particle size changes which reflect the stability of SC suspension were studied. The results showed that when the contents of GY-D10 dispersant were 4 wt% in the SC, the stability of SC suspension system was relatively good.