In this work, based on Kiparissides ? s model for polymerization of poly (vinyl chloride) (PVC) and the model presented by Xie et al. for diffusion-controlled reactions, a user -friendly software has been developed. Kinetic parameters, operating conditions and reactor geometry are input data in this software. Mass balance equations for monomer and initiators, phase equilibrium equations and the equation related to anomalous structures observed in chains of PVC are solved by software. Synthetic and operating parameters (e.g. conversion, reaction rate, reactor pressure, and etc.), molecular weight of polymer (M w , M n , Kvalue) and structural characteristics (S d , L d , T n ) are output data of software that can be illustrated in diagram and table schemes. Validation of software is done by using experimental data reported in literature. It is shown that experimental data on the conversion, reactor pressure and final product Kvalue are in good agreement with model predictions. However, at high conversions a very good agreement between experimental data and model predictions is obtained. The effect of continuous initiator dosage on reaction rate and final products properties were investigated. Simulations results showed that in continuous initiator dosage technique, the types and the initiator dosage regime are the main factors affecting the increase in polymerization rate before occurrence of critical conversion. Initiators with half- life lower than 0.4 hours which are the so-called “fast initiators” are suitable for this technique. The suitable initiator dosage regime consists of two steps. In a first stage which lies in the beginning of the reaction, the rate of initiator injection is significantly high. The second stage, which involved major part of polymerization course, the rate of initiator injection is lower than first stage and tends to a value close to zero at critical conversion. Using an suibable fast initiator dosage regime, it is possible to keep the reaction rate at its maximum permissible value. It is found that a suitable dosage regime allows the total polymerization time to be reduced by as much as 38.9 percent, while the final conversion remains unchanged from standard polymerization. However, use of initiator with half- life more than 0.58 hours at the polymerization temperature at the beginning of reaction is recommended to achieve a high conversion. Keywords: PVC, continuous initiator dosage, Kvalue