The results of calculations of thermal deformation tensor and its analysis are given for eleven silicates and vanadates of clinopyroxenic structure. It is shown that the level of thermal deformation anisotropy in monoclinity plane is in stable correlation with velocity of monoclimity angle change. The correlation is explained by considerable contribution of shear component into deformations. Considering the shears it is possible to understand, to separate the thermal deformations in monoclinic crystals into components and to summarize them from those components. The given regularities permit generalisations for triclinic crystals as well as for pressure and chemical (compositional) deformations.