Abstract: The polymerization kinetics model of vinylidene difluoride was deduced based on the oligomer mechanism of dispersion polymerization and the theories of free radical polymerization in this paper. The relationships of reaction rate (Rp) and particle number per unit volume (Np) with initiator concentration (ρI), monomer concentration (ρM) and emulsifier concentration (ρS) in a horizontal reactor were studied. Under the reaction conditions, Np=1.01×1019ρ1.92Sρ0.10I,0ρ-3.11M,0 and Rp=1.76×10-8×Φ1/3ρ 0.36Sρ 0.60Iρ 3.83M were acquired. Compared to VDF dispersion polymerization model, the equation of Rp can be further rearranged and the effect of Np on Rp is the exponent of 0.19, similar to the model value of 1/6. According to the definition of K0 and the parameter values from literature, partition coefficient (α), which is the ratio of VDF monomer in the water phase and in the reaction area, is 1.50×10-4 by calculation.