Shallow seismic reflection survey is more complex than conventional oil exploration because of coherent and random noise, and the most important factors connected with this method are high S/N ratio and high resolution. This paper deals with the key technique of the portable vibrator system, whose correlation and tapper processing can restrain random noise and improve resolution greatly. The vibrator seismic source is of longer duration and generally lower amplitude than dynamite sources, with relatively less damage to ground and nearby structures. Field practice has demonstrated that the portable vibrator system can indeed serve as a nondestructive, controllable and highresolution technique. This technique has already been applied successfully  in the field of hydrology as well as civil and environmental engineering.