In study of polynitrocompounds it is found that a dense crystal must not necessarily be constructed from dense molecules,and the main factors affecting the crystal structure are the electronic structure of their molecules.The correlation between the value of non-bonded intramolecular contact and the magnitude of the respective intermolecular contact seems to be unusual for this kind of Compounds.Alkoxydiazene-N-oxide and 1, 1, 4, 4,-tetranitrobutanediol-2,3 derivatives were taken as examples in this study.The obtained results concluded that the intramolecular interaction can stabilize the crystal conformation,while the increase in the intermolecular contact decreases the crystal density.