Objective To study the relationship between comfort and sitting pressure of ejection seat cushion. Methods By measuring sitting pressure distributions on seat cushions with different thickness, indices of sitting pressure such as the contact area, maximum sitting pressure and mean sitting pressure were discussed along with the subjective comfort scores to find the relationship between seat cushion comfort and indices of sitting pressure. Results The contact area, maximum sitting pressure and mean sitting pressure were significantly correlated with the subjective comfort scores. In addition, the comfort score did not increase when thickness of the seat cushion exceeded 4 cm. Conclusions The comfort of seat cushion could be well reflected and evaluated by the contact area, maximum sitting pressure and mean sitting pressure of seat cushion, and thickness of 4 cm is recommended for designing the seat cushion with material used in this paper.