A system for exploration of active-faults by seismic reflection profiling method was introduced at Earthquake Research Institute, University of Tokyo. A test-run was conducted to check the performance of this system at Ranzan, Saitama Prefecture. This paper describes the confirmed performance of mini-VIB as a wide band frequency seismic source, the quality of data obtained using a digital data acquisition system, and problems for data processing of fault exploration in the future. For the test-run at Ranzan, two-dimensional exploration was conducted by the quasi-three-dimensional data acquisition method using three geophones of 8 Hz, 28 Hz, and 40 Hz, simply arranged in parallel on the measurement line. Using an active seismic vibrator, mini-VIB, data acquisition of faults in the wide band frequency was achieved, which would result in the highly accurate imaging. Operation of data acquisition and processing systems is easy, and the system can be also used as a kind of black box. The existing methods are to be used sufficiently as a tool for imaging of faults. Further research for accumulating experience may become necessary toward the extension of the system expected in the future. 5 refs., 6 figs.