Abstract: Stretcher is an important medical apparatus in fieldrescue operations, but for a common stretcher, it is not easy to keep its boardhorizontal when used on slopes (such as on stairs or steep mountain roads). Thispaper studies the parallel four-bar mechanism and its mechanicalcharacteristics. Based on the analysis, a new type medical stretcher canbe designed. This new type stretcher can keep itsboard and handles horizontal not only on a plain ground, but also on slopesituations, with easy operations. This apparatus holds a bright prospectfor its applications in the field rescue operations.