Effect of different solvents on thermal decomposition of RDX was studied by using special Bourdon manometer. Solvents can accelerate,inhibit or do not affect decomposition of RDX: (1) inert solvents,such as benzene,naphthalene, isooctane, do not affect decomposition rate of RDX; decomposition rate in these solvents is the same as that in melt state; (2) solvents,like aliphatic-aromatic compounds,alcohols,ketones,ethers and esters,increase decomposition rate of RDX; (3) solvents with large viscosity inhibit thermal decomposition of RDX.