The laser monitoring observation technique is proposed to measure the solubility and supersolubility of RDX in different proportion and temperature for the antisolvent crystallization. Experimental determination of the solubilities curve and the metastable zone widths (MSZWs) are presented. Knowledge of the solubility curve and the stability of the solution in the vicinity of the equilibrium point, as indicated by the MSZW, is essential to the successful development, optimization, and scale-up of a crystallization process. Then the solubility characteristic in acetone is correlated by Apelblat empirical equation and the solubility characteristic and the supersolubility characteristic in binary mixed solvents of acetone-water are correlated by (CNIBS)/Redlich-Kister equation, all the RMSDs of models are less than 0.001.