A parameter optimized simple matrix (POSM) model is proposed for characterizing the liquid crystal display (LCD) monitor with variant primary chromaticity and primary crosstalk. This method is the same as the conventional simple matrix (CSM) model except that black point, white point, one-primary measurement data, and two primary measurement data are taken as the training samples for optimizing the signal nonlinear transformations (SNTs) and chromaticity matrix. As the configuration of the POSM model is the same as the CSM model, its backward model is simple and can be implemented for video applications. Polynomial function is taken as the SNT. The optimization process comprises the simulated annealing method for optimizing the coefficients of SNTs and the regression method for calculating the chromaticity matrix. The results show that the average color difference (CIEDE2000) of 224 random test samples for two characterized LCD monitors are 2.02 and 1.33 with a forward POSM model, and are 2.32 and 1.27 with a backward POSM model. The primary crosstalk of the LCD monitor with a higher average color difference is more serious than the other monitor. The performance of the POSM model is much better than the CSM model. For the monitor with lower crosstalk, the POSM model is better than the three-dimensional look-up table (3D-LUT) model with a 5 × 5 × 5 lattice but is worse than the 3D-LUT model with a 8 × 8 × 8 lattice.