Results of X-ray investigations of dependence of the crystallographic texture of hafnium and zirconium on degrees of cold rolling are presented. To obtain numerical principles, the method of inverse pole figures (IPF) with calculation of the texture parameters of Kearns (TP) for a chosen direction has been used. Measuring was carried out in the plane of the plates, as well as in the other two directions relating to rolling. The trigonal diagram of TP changes with degrees of deformation was built. Two stages of TP changes with deformation degrees are revealed: rate of the TP changes at the initial stage and, in part, characteristics of the subsequent stage depend on the initial texture of the materials. The second stage is characterized either by achievement of a minimum of TP in the rolling direction of the plates, or by moderate and even slight changes of them. In an example of hafnium, it has established that the increased rate of initial changes in TP is exclusively associated with intensive twinning predominantly by the {10‾12} <‾1011> system. Arguments for dominance of twinning in the texture formation in hafnium and zirconium on the subsequent stage of rolling deformation are given