U Urban areas usually have complex pollution problems due to various activities such as industries, trades, and transportation. The last activity, specially motor driven vechile, is a anthropogenic activity which had been accused to be the sources of air pollution. Carbon monoxide and hydrocarbon are among gasses released by motor driven vehicle whre the effect of both gasses can be felt in big cities. High concentration of carbon monoxide can be fatal when reacted with blood's Hb, which decreased the ability of blood to transfer oxygen. Meanwhile, hydrocarbon is a part of photochemical oxidant production which involve NOx to form PAN (Peroxy Acrtyl Nitrates). Among the three locations of measurement, the highest average of concentration CO and HC is located in Pandanaran where the average is as high as 4196.44 ug/m kubic and 942.24 ug/m cubic respectively. Whereas the lowest average lies is Imam Bonjol area where the avegae is as low as 2537.94 ug/m cubic and 704.53 ug/m cubic respectively. The concentration of CO has not yet passed the tilerated limit, but the concentration of HC has already passed the tolerated limit. The tolerated limit used is based on goverment regulation number 41 year of 1999 where the tolerated limit for CO is 10000 ug/m cubic and for HC is 160 ug/m cubic. The analytical linear regression between the population of vrchicle and the concentration of CO and HC shows that motor driven vechicle has a significant and strong effect to the cocentration of CO and HC. this is shown by the significant value where the value is lower than 0.05 (between 0.004 and 0.007). As for analytical correlation, it is also shown than the population of vehicle is strongly affected the concentration of pollutant because the value of R is large than 0.5. Based on field measurement and calculation using Gauss model, differentiation has been found. The result of the calculation is lower than the field's concentration during daylight where the result of the calculation is large than concentration during nightime. Some action are required to be taken to control the concentration of the pollutant. Action that are related to motor driven vehicle is a must since the higher the population of motor driven vechicle, the higher the concentration of pollutant.