A new method is proposed to evaluate in situ hydraulic properties of formations using the so-called pressure pulse test over sort test inverals. The analysis utilizes the cotinuous distribution of instantaneous ring sources of fluid over the well bore surface in order to reduce the problem to a set of singular integral equations for a homogeneous and isotropic porous medium. When the ratio of the test interval length to well bore diameter is small, or the specific storage is small, the flow parallel to the well bore axis becomes significant, and the shape of the type curves obtained from the present analysis is different from that of the conventional type curves. Use of the conventional type curves should be restricted to intervals that are more than 20 times longer than the well bore diameter. Finally, the present method is applied to evaluate the in situ hydraulic properties of the Higashi Hachimantai geothermal model field of Hot Dry Rock, Tohoku University. ¿ American Geophysical Union 1987