In this study a typical continuous lumping model with five parameters has been used for kinetic modeling of thermal and catalytic hydrocracking. Model parameters have been optimized according to experimental product distributions using a particle swarm optimization (PSO) algorithm. Experimental data from the hydrocracker setup have been employed to validate the proposed model. In this setup hydrogen and vacuum gasoil feed were introduced from the top of a vertical reactor and, after passing through a catalyst bed, the liquid and gas products were separated and analyzed. Temperature of the reactor was adjusted in the range of 440-470ºC for thermal hydrocracking, and 410-430ºC for catalytic hydrocracking. Liquid hourly space velocities (LHSV) were in the range of 0.5-1.5 feed flow rate per catalyst volume in both sets of experiments. Results of optimization showed that the parameters were only temperature dependent. The comparison between model results and experimental data indicates that the model is capable of predicting product yield with maximum errors of 0.986 and 0.041 for RMSE and AARE values, respectively.