This paper describes an experimental study of growing ductile crack-tip behaviors by means of computer image processing technique and finite element method. Here, the displacement field near a crack-tip is first measured by the computer image processing technique. Combined with the finite element technique, strain and stress fields are evaluated from the measured displacement. Then, crack-tip parameters such as J-integral are evaluated using the obtained displacement, strain and stress fields. The present technique is applied to a growing crack problem of tensile CT specimen made of 304 stainless steel. The ductile crack growth behaviors accompanied by unloading are discussed in detail through the comparison between the experimental and the theoretical results.