A laser remote detection technique is applied to measurement of low airflow velocity. Detection of tracer particles, analysis for air flow velocity and application of the detection system are described in this paper. For the detection of tracer particles, a remote laser detection system is used. It consists of a He-Ne laser, a TV system with an image intensifier, a VTR, etc. The laser beam is scanned through the measuring space, and the scattered lights of the tracer particles are detected by an image intensifier and TV system. The image data are analyzed by following procedures : 1) digitization of the visualized image, 2) labeling of tracer particles, 3) tracing of particle image, 4) determination of the air flow direction, 5) calculation of airflow velocity. Comparison experiment of the system with a ultrasonic anemometer is conducted. There is a good correlation between the air velocity values obtained by the two instruments. Furthermore, the detection system is applied to measurement of air velocity near surfaces.