Abstract：It is well known that rock properties often vary from site to site，and even from specimen to specimen. So，in many cases，it requires many rock samples，much effort and cost to obtain the reliable data. In order to make more rock samples to carry out rock mechanical strength tests in the laboratory，a testing method with a small rock specimen (10 mm in diameter and 20 mm in length) was proposed and developed. In the triaxial compression test，the transparent triaxial vessel made of an acrylic acid resin，developed by Okubo et al.，was modified and used for the small specimen. The transparent vessel was designed for triaxial compression test under confining pressure up to 10 MPa. It was found that the mechanical parameters，cohesion and angle of internal friction，of Tage tuff with small specimens are very similar to the results obtained from regular specimen. Furthermore，the loading rate dependency of a stress-strain curve was also obtained by just one small specimen with the loading rate alternately switching during a test. The rock collected from landslide area near the Three Gorges Reservoir was also examined. By the proposed method，the strength characteristic curve and the loading rate dependency of the sample rock were accurately and economically obtained.
