An optical remote sensing method based on passive differential optical absorption spectroscopy for the measurement of the distribution of city gaseous pollutant was studied. The passive DOAS system, which was installed in a car, successively measures the interested area (such as city, industrial area) and the column density was obtained by DOAS fitting process using the zenith scattered sunlight. The mobile DOAS was applied to measurement in Shenzhen City during the continuous six days and got the distribution of SO2, NO2 in this paper. It showed that the pollution in the west is higher than in the east. The average concentration in the west is 2.0 times higher than the eastern for SO2 and 3.6 times for NO2. And comparison of the values between mobile DOAS and the point instrument was carried out in Baguang site. There was an agreement between the two instruments, the correlation coefficient was 0.86 for SO2, while 0.57 for NO2. The results indicate that this optical remote sensing method based on passive DOAS is an effective means of rapidly determining the distribution of city gaseous pollutant.