Abstract: Ten month(December,1978-September,1979)ECWMF reanalysis data was employed as quasi-observational boundaries to drive PRECIS at 25km horizontal resolution over Ningxia to analyse the sensitivity of model simulation to 4 different domain sizes via comparing the simulated daily mean temperature and precipitation in summer and winter to with the observation.The results showed that the daily mean temperature and precipitation could be well simulated by PRECIS at 25km horizontal resolution over Ningxia in 4 kinds of different domain size,the PRECIS especially performed better for precipitation simulation.It can be seen that the PRECIS simulation was sensitive to the model domain size,the simulated results were declining when the domain size decreasing,however,the PRECIS simulation was still well in the mid-small domain size over Ningxia.Considering the expenses of calculation,the mid-small domain size was the most efficient to climate simulation in Ningxia using PRECIS at 25km horizontal resolution.

Key words: PRECIS, PRECIS, Domain size, Climate simulation