Abstract: In order to explore the influence of armrest support on the mouse operation of VDT operators, the Dxracer FE0 office seat with adjustable armrest support was adopted. 30 VDT operators were selected as subjects. Mouse operation test was conducted using Aim booster software to obtain test data in two states with and without armrest support. The results show that the mouse click accuracy and hit times are higher when there is armrest support than when there is no armrest support. The average reaction time of mouse clicks with armrest support was higher than that without armrest support. Gender has an impact on mouse click performance. Some suggestions on seat armrest setting are put forward for different mouse operation tasks.