Abstarct: One of the biggest concerns of crude oil-producing countries is the leakage and penetration of oil into the environment during the various stages of extraction, transportation and processing of petroleum products. Iran is one of the countries rich in oil in the world, where large amounts of oil are extracted from its south and refined in other parts every year. Oil pollutants can be absorbed on the surface of soil particles and enter the underground water along with the surface currents and finally enter the human, animal and plant food chain. A wide range of heavy mextals are found in different quantities along with crude oil compounds, and in case of crude oil leakage and penetration into the soil, the accumulation of these mextals in the soil endangers the health of the soil and humans. According to the existing reports about multiple breaks of oil transmission pipelines in Miankoh region, Chaharmahal-va-Bakhtiari province, it is necessary to assess the risks of oil entering the agricultural lands of the region in order to prevent the transfer of pollutants to the human food chain. The current research intends to determine the impacts of crude oil compounds entering the soil on important soil characteristics, including soil reaction, percentage of organic matter, percentage of total petroleum hydrocarbons (TPH), soil microbial respiration, concentration of available phosphorus and total concentration of lead and cadmium heavy mextals. To conduct this research, first, five separate areas, including the area adjacent to the oil pressure pumping center, the area downstream of the leaking pipes, the area downstream of the broken pipes in 2012, the area downstream of the broken pipes in 2021, and the area upstream of the oil transmission pipelines, were delineated. Then, 3 surface soil samples (0-20 cm) were collected from each area and transported to the laboratory for chemical analysis. After preparing the soil samples and passing them through a 2 mm sieve, important soil properties were measured using standard laboratory methods. The statistical analysis of the data was done using mean comparison baxsed on Duncan's test applying SPSS software, version 21. Meanwhile, Excel software version 2013 was used to prepare the relevant charts. This research was carried out baxsed on a completely randomized design. The results showed that with the accumulation of crude oil in the soil, most of the examined characteristics underwent significant changes. The lowest amount of soil reaction is related to area number 2, i.e. the lands located downstream of the broken pipes in 2013 and is equal to 7.53; while the highest amount of this important soil chemical characteristic was 8.06 and it was observed in the lands downstream of the oil leaking pipes. The lowest percentage of soil organic matter (1.34%) was obtained in the control lands, and the value of this feature was significantly higher than the control lands in all areas affected by crude oil infiltration. The highest value of this key soil characteristic was observed in the lands of area No. 4, that is, the area downstream of the crude oil leaking pipes.