C Composition and concentration of air substances are determined by the substances that are being emitted from certain sources. Motor vehicle activity is the main element in causing air pollution. The incineration process in motor vehicles produced toxic exhaust such as Hydrocarbon (HC) and Sulfur Dioxide (S02).HC pollutant can be produced by a natural process (natural oil and gas wells) and humanactivity (motor vehicle exhaust}. The decaying process of organic substances can produce S02 pollutant naturally and also can be produced from human activity such as motor vehicle exhaust. There are three types of fuel, i.e. gasoline, diesel fuel and gas. There are two ways to calculate HC and S02 concentration, that is to use Gauss calculation and field measurement research.The scale that was being practiced in this field researched is a full field scale, not a laboratory scale. The device used in measuring HC is Hydrocarbon analyzer type GHC-75M using chromatograph gas. And SOx analyzer type GFS-32 is being used to measure S02 using Ultraviolet Fluorescence method. Measurements re conducted in early October 2001 at 8 measurements points by using the MULPU vehicle. tatistic analysis method was being used for data analysis and the overcome results from Gauss calculation and field research were being compared to the quality standard (PP No. 41 ahun 19 9',The highest result of Hydroca ban ve age in fi Id m asurements was located at T. Cicaheum (1751,26 µg/m3) and th I st wa locat at K D 467,36 µgtm3>. The highestresult of S02 was located at the Dipone oro (90, µ~ . 3) and t e lowest at Cibiru (61,78 µglm\After being converted to the Cou ter t ula an co 12ared t the 9uality standard, apparently the amount of HC that was bein~ m • the field ed the quality standard range(HC quality standard= 160 µg/m for 3 ho. s. tin• r tical calculation, the amount of HC didn't exceeded. In the other haACI th am u t of 2 ittl • om field measurement or theoretical calculation, was still in the quality standard range (S02 quality standard= 265 µg/m3 for24 hours).Why the theoretical measurements result was smaller than the field measurement result is because of the large amount vehicles, the changing wind direction and velocity that would bring pollutant to the measurement area, vehicles emission factor are being assumed similat, the stability class only calcutate wind velocity and sun radiation, buildings and vehicle speed produced wind dispersion -that- could cause the instability of the wind, and other environment factors that consist in the• measumment area. From statistic analysis, the strongest correlation for HC was located at M.Toha Street {0,994) and the weakest was at the Cibiru traffic circle (0,617). From the significant results, Jhe .best HC result was located at M. Toha Street (0,001) and the weakest was at Cibiru traffic circle (0,204). Andfor S02, the strongest correlation was located at Elang Raya Street ( 0, 777), the weakest was at Cibiru traffic circle (0,507}. From the significant result, the best S02 result was located at Elang Raya Street (0,013) and the weakest was at Diponegoro Street (0,396).The overall conclusions are that the theoretical calculation results are always smaller than the field measurement results, the amount of motor vehicles is effecting the concentration ofHC and S02 with different significant value. According to PP. No. 41 Tahun 1999, based on the field measurement, the amount of HC has exceed the quality standard but the amount of S02 is still in the quality standard range. Crucial suggestions to be noted, the need of Air Monitoring Station, fuel check and motor vehicle treatment, the need of toxic emission pollutant reducer devices, market an environmental friendly motor fuel, conducted an emission test for vehicles, and vehicles restriction in certain areas at certain times.