Abstract: Based on the Lagrangian change equation of vertical vorticity deduced from the equation of three-dimensional Ertel potential vorticity(PVe),the development and movement of vortex are investigated from the view of potential vorticity and dia-batic heating(PV-Q).It is demonstrated that the asymmetric distribution in the vortex of the non-uniform diahatic heating in both vertical and horizontal can lead to the vortex's development and movement. The theoretical results are used to analyze the development and movement of a Tibetan Plateau(TP) vortex(TPV),which appeared over the TP,then slid down and moved eastward in late July 2008,resulting in heavy rainfall in Sichuan Province and along the middle and lower reaches of the Yangtze River. The relative contributions to the vertical vorticity development of the TPV are decomposed into three parts:the diahatic heating,the change in horizontal component of PVe(defined as PV2),and the change in static stability θz. The results show that in most cases,diahatic heating plays a leading role,followed by the change in PV2,while the change of θz usually has a negative impact in a stable atmosphere when the atmosphere hecomes more stahle,and has a positive contribution when the atmosphere approaches neutral stratification. The intensification of the TPV from 06:00 to 12:00 UTC 22 July 2008 is mainly due to the diahatic heating associated with the precipitation on the eastern side of the TPV when it uplifted on the up-slope of the northeastern edge of the Sichuan basin. The vertical gradient of diahatic heating makes positive(negative) PVe generation below(ahove) the maximum of diahatic heating;the positive PVe generation not only intensifies the low-level vortex but also enhances the vertical extent of the vortex as it uplifts. The change in PVe due to the horizontal gradient of diahatic heating depends on the vertical shear of horizontal wind that passes through the center of diahatic heating. The horizontal gradient of diabatic heating makes positive(negative) PVe generation on the right(left) side of the vertical shear of horizontal wind. The positive PVe generation on the right side of the vertical shear of horizontal wind not only intensifies the local vertical vorticity but also affects direction of movement of the TPV. These diagnostic results are in good agreement with the theoretic results devel-oped from the PV-Q view.