The micro-earthquakes (M<4) data has been used to obtain velocity structure and azimuthal anisotropy in the Tehran region up to 3 km depth. These earthquakes were recorded by the Tehran Disaster Mitigation and Management Organization (TDMMO) seismic stations between 2006-2018. Strict criteria were applied (including minimum and maximum epicentral distances, signal-to-noise ratio, two times of wavelength for each epicentral distance, etc.) for selecting a subset of data. The velocity model indicates a low velocity anomaly near the Hezardareh geological units which is caused by a thick sedimentary layer. Also, the crushing zone appears as a low velocity anomaly in the north part of Parchin, Rey, and the junction of Kosar-North Tehran faults. However, the fast direction is parallel with North Tehran-Rey in the Tehran basin, while it rotates in the east part of the Parchin fault.