In order to study the microscopic features of Beijing’s temperature data, an asymmetrical CARCH model is set up for Beijing’s daily average temperature data, daily minimum temperature data and daily maximum temperature data during 1952-2006. The results show that Beijing’s temperature has a rising trend overall. However, daily maximum temperature and daily average temperature will rise in a limited range, and daily minimum temperature will rise in a larger extent; the changing ranges of daily maximum temperature and daily average temperature will be in a limited extent, but the changing range of daily minimum temperature will be in a larger scope.Temperature warming makes sense to the rising trend on all scopes, but cooling only makes sense to the daily minimum temperature.