In this study, the performance of Coupled Model Intercomparison Project Phase 6 (CMIP6) models in simulating the temperature extremes, including the annual maximum of daily maximum temperature (TXx) and annual minimum of daily minimum temperature (TNn) over the mid-high latitude of Asia are comprehensively assessed, as well as their future changes. The main findings are as follows: 1) The observed extreme temperature gradient from south to north and west to east over the mid-high latitude of Asia are reasonably reproduced by most CMIP6 models, but the cold bias is still obvious over the Tibetan Plateau. Additionally, the higher skill is generally observed for the climate mean simulation of TNn than TXx, while a relatively stronger skill is for TXx for the trend simulation. The multimodel ensemble mean (MME) generally outperforms the individual models. 2) Results of future projection indicate that both TXx and TNn show a significant increasing trend in the 21st century, but the increase magnitude of TNn shows much greater than that of TXx. Under the SSP5-8.5 scenario, TXx and TNn are projected to increase by approximately 7.0°C and 9.6°C by the end of the 21st century with respect to the current state (1995-2014), respectively. The projection uncertainty is estimated to increase with time and scenarios, and the increase of TXx shows a higher model agreement.