Seating pressure sore is always one of main problem for rehabilitation engineering and biomedicalengineering. Many people need to stay much time in the chair owing to work and sick, resulting inuncomfortable and pressure sore. For relieving pressure sore and providing the information used inclinical diagnosis, in this research, a clinical instrument is designed to assess pressure distributionand at last suggest the proper posture and cushion. The evaluation system include the adjustedposition system-adjusting character of variable body, interface pressure system and buttock contoursystem.From the result of experiment, one can see that the max. pressure in the spinal cord injury isgreater than that in the normal people and as the seat angle and seat to back angle increase,themax. pressure decrease. one can understand spinal cord injury easily get the pressure sore thannormal people do. We use the appropriate seat and seat to back angle to reduce the interfacepressure to prevent the pressure sore.