Abstract:A high temperature weather process occurred in central and northern part of Ningxia from August 6 to 10 in 2011. Using conventional observation data, hourly ground observation data of mesoscale regional automatical weather stations and NCEP/NCAR 1°×1° reanalysis data, this paper analyzes the horizontal and vertical structure of the Tibetan high which has close relationship with the high temperature weather process. The results show that： Tibetan high is a thick warm negative vorticity system, whose inphase superpostion with the westerly long wave high pressure ridge strengthens the long wave high pressure ridge and warm high pressure over Tibetan plateau. The 586 dagpm line of the periphery of Tibetan high passes over Tibetan Plateau and maintains steadily near 85°-105°E, and the north boundary of Tibetan high extends to 40°-42°N. Most parts of Northwest China are under the control of Tibetan high over 584 dagpm and surface thermal low under 1000 hPa for a very long time. Polar front jet and upper level jet interact over Tibetan high, and the circulation converging in upper level and diverging in low level results in strong sinking motion over eastern Tibetan Plateau. It was cloudless in Ningxia where is located in that sinking motion region with low humidity, relatively high wind speed, strong warming and evaporating at ground and the surface sensible heat was much higher than latent heat. All these factors are benefitial for the occurrence of consistent high temperature weather. Finally, this paper proposes a conceptual model for summer high temperature weather in Ningxia.