Particle morphologies and particle size distributions of polyvinylchloride(PVC) paste resins made by different production methods were investigated by scanning election microscopy (SEM) and laser particle size analyzer. And the effect and mechanism of these PVC paste resins on viscosity and stability of corresponding PVC plastisols were also discussed in detail. The results show that the PVC paste resins made with micro-suspension method, seed micro-suspension method, seed emulsion method and hybrid method have the lowest, secondary, tertiary and largest viscosity respectively. In addition, the results reveal that corresponding PVC plastisols composed of PVC paste resins with seed micro-suspension method possesse the optimum stability, and the secondary with micro-suspension method as well as seed emulsion method, the most inferior with hybrid method.