Abstract: Aiming at the low efficiency of mode switching in pen user interface,mode switching techniques are designed and evaluated.First,6 mode switching techniques which are pen-pressure-trajectory,pen-tilt-trajectory,pen-azimuth-trajectory,pen-pressure-discretization,pen-tilt-discretization and pen-azimuth-discretization are designed according to pen-modality-trajectory and pen-modality-discretization by using pen pressure,pen tilt and pen azimuth modalities.Second,the comparative experiment of color and thickness adjustment in the process of painting is designed and carried out on the Wacom Intuos 3 to evaluate the performance of the mode switching techniques and the referencing technique.The experimental results showed that the pen-pressure-trajectory technique has the best comprehensive performance.Its time consumption is reduced by 20.13%and its comprehensive performance is improved by 37.68%compared to the referencing technique.The time consumption of pen-tilt-trajectory technique,pen-azimuth-trajectory technique and pen-azimuth-discretization technique are reduced by 11.12%,2.65%and 10.70%respectively compared to the referencing technique.The error rates of pen-tilt-discretization technique and pen-azimuth-discretization technique are reduced by 62.82%and 32.38%respectively compared to the referencing technique.Last,the performance of mode switching techniques are analyzed,and the improvement measures of mode switching technique such as setting reasonable threshold,analyzing context environment and selecting appropriate switching level are given.