From January to March 2000, water injection experiments were carried out near Nojima fault which ruptured during the Jan 17, 1995 Kobe (Hyogoken-Nanbu) Earthquake. During these experiments we measured the temporal variation of seismic velocity around the pumping well using an accurately controlled vibration source (ACROSS). ACROSS vibrator is an instrument that produces sinusoidal wave with a centrifugal force of a rotator. Two ACROSS vibrators were firmly placed on the granite ground near the site. They were continuously operated over three months including a series of pumping operations. The waves generated by vibrators are detected with geophones deployed at the bottom of the wells of 800m and 1700m deep, which are very close to the fault. The data are repeatedly stacked with 100sec interval and are stored at every one-hour. The ACROSS vibrators were operated using frequency modulation of 13.00 2.1Hz and 19.1 2.1Hz with a modulation period of 5seconds. This operation produces plural components of sinusoidal waves between about 10 and 22Hz with an interval of 0.2Hz. Applying inverse Fourier transformation to the observed signal, we obtained a signal of time domain, in which P and S phases appear clearly. With the calculation of cross-spectrum of P and S phase between traces, their temporal variations are calculated. We obtained continual variation for over three months. Travel time of the S waves between geophones of the two wells increased by about 300 Esec after the second pumping operation. This corresponds to the velocity variation of about 0.1\%. The change is recovered after the pumping operation by about 100 sec for 20 days. In contrast to the S wave, little variation is observed in the travel time of P wave. This may indicate that the variation is caused by the increase of density of fluid-filled cracks with the injection of pressurized water.