The direct tensile test of composite resins using the specimen with the gauge length 10mm has been developed by authors.In this study smaller specimens with the gauge length 5mm and 2mm were also investigated.As the gauge length became smaller, tensile properties such as the proportional limit, the proof stress, and the tensile strength showed the tendency to become higher.The effect of strain rate on the tensile properties appeared clearly when using the specimen with the gauge length 2mm.The small specimen was found to have many advantages for the preparation, the cost of material and the handling during the tensile test.