Abstract: Using anthropological method and anthropometric data analysis, the author studied and discussed the man-machine system of auto cab in this paper.
a) The items of stature, shoulder height, sitting height, sitting eye height, sitting shoulder height, upper- and fore-arm length, thigh and shank length, shoulder breadth, sitting depth, buttock-knee length, stomach depth, chest breadth of more than 700 adult workers in Beijing and Sichuan have been measured.
b) The data were analysed by micrioeomputer. The regional and sex groups were conducted and the means, the standard deviations, the ranges and other statistics of the dimensions were listed.
e) The data of osteometry were used so that some dimensions could be rectified. In this way, the position of“H"point, the distance between the center of shoulder joint and elbow joint as well as that between the“H"point and the axis center of knee joint were defined. Then, the 5th and 95th per cent body movement models (BMM) of Bei- jing and Sichuan male population were built.
d) The optimum depth, breadth and height of the pad, the angle formed by horizontal and seat as well as back, maximum area for hand, the distance between pads and back, and so on, were discussed. An optimum scheme was obtained. For all items stated above, the 5th percent BMM of Sichuan and 95th percent BMM of Beijing were con. sidered to be the lower and upper limits. Comparing with the Standard of Truck Driver's Operation Position by The First Ministry of Machine-Building of China (JB 2667-80) , the author found that there are some differences in workspace design. The author considered that the proposal mentioned in this paper is more suitable for the popnlation in China.
e) According to the analyses of 10 male adults'back-lumbar profiles and the electromyographs of the longest muscle, it is pointed out that a lumbar cushion is important to prevent drivers from hurt on intervertebral discs. The shape of pad was discussed in this paper too.

Key words: Auto-cab; Workspace; Anthropometry