Abstract: Aiming at the differences of pen modality inputs in different screen regions,the influences of screen regions on pen modality inputs were investigated.At first,two pen input tasks which were writing task with unrestricted trajectory and sliding task with restricted trajectory were designed.Then,the performance of pen modality inputs in different screen regions was empirically explored on Wacom Cintiq 21UX.The experimental results showed that in the polar coordinate system whose pole coincided with the vertex of a screen corner,the pen modality values increased with the polar diameters,and power or linear relationships were found between the pen modality values and the polar diameters.The extreme values of each pen modality usually appeared in the corner regions of the screen.For the right-handed users,the pen tilt angle on the upper side of the screen was usually larger than that on the lower side of the screen.The pen azimuth decreased and then increased along with the position of the screen regions clockwise.The number and the location of screen regions significantly influenced the interaction performance.With the increase of the number of screen regions,the mean differences between screen regions decreases.According to the sliding speed,the release error rate,the out-of-path rate,and the deviation from tunnel center,the comprehensive performances of small regions,the central regions,and the upper regions were better than those of larger regions,the surrounding regions,and the lower regions.At last,the suggestions of interaction design with screen regions are given,which provides reference for the pen modality interaction with screen regions.