In order to investigate the fluctuation phenomena of RDX crystalline particles subject to pressing,the compression stiffness tests (CST) were conducted for five types RDX crystalline particle ensembles from three sources and it is found that the fluctuation of the compression relates closely to the coherence strength of single particle of RDX. The measured fluctuation amplitudes of recrystallized is about 2.4 MPa,which is much higher than that of commonly used RDX,namely 1.2 MPa,and D-RDX bears the highest fluctuation amplitude of 4.4 MPa,it means that recrystallized RDX (D-RDX) has a maximum allowable failure stress and its quality has been well improved compared to the rest of the samples. This study shows that when using CST to evaluate the quality,the fluctuation should be considered carefully.