A stretch fabric material having an elongation of at least 20% in the warp direction is provided with both of the stretchability and the stiffness, which is composed of a Raschel warp knit fabric formed of non-stretchable fiber yarns having no rubbery elasticity, wherein loops of tuck warp are engaged with loops of a ground fabric structure. Since the stretch knit fabric material of the invention exhibits a gentle tightening force when covering or bandaging a human body, it is suitably used for a medical material for covering or bandaging a human body having curved or irregular portions, a reinforcement material for a molded object having curved or irregular figure or portions, a stretchable bandage, a casting tape or a splint for orthopedic surgery use.