The urban ventilation path can help to alleviate the heat island effect and air pollution. The building ventilation method is based on building front area density, the building data is divided into grids with numerical attributes, to detect ventilation path. The urban morphology is including building and street, while this building method ignores the ventilation path of the urban street. The streets are most closely connected with people’s lives. The direction of the street is the main evaluation index to extract the street ventilation path, which is the supplement of the building method. The spatial analysis technology of Geographic Information System (GIS) was used to calculate the front area density, the street direction, the street length, and the street aspect ratio. These indicators are related to ventilation potential and simulated by Computational Fluid dynamics (CFD). Under different wind directions including the vertical and parallel to the street, it found that the street ventilation potential is different as to the street aspect ratio, if the wind direction is parallel to the street, the street ventilation is better with the decrease of street aspect ratio; if the wind direction is perpendicular to the street, the street ventilation is better with the increase of the street aspect ratio. In the grids of high front area density, there are also some potential ventilation urban streets.