Abstract: The process of the low level shear line formation over China during 17 to 19 June 1960 is investigated by calculating and analysing some of its physical factors. Some dynamical influences of the Tibetan plateau are estimated quantitatively. The orographic friction effect seems to be important for the evolution of the local circulation. Tentative numerical-experiments for the formation of shear line are made with one-and three-levels quasi-nondivergent models, starting with ideal and actual initial flow distributions. The processers calculated are similar to that of the actual shear line formation in the main respects.