Abstract In most communities, soil contamination is a problem as it affects people and the environment. Because oil spills on soil substantially impact the environment, accidental infusions and spills of ore oils frequently result in a complete or partial exchange of the soil pore fluid by oil-contaminated soils, altering the geotechnical engineering characteristics. Therefore, efficiently removing petroleum hydrocarbon pollutants from contaminated soil is urgently needed. A novel technique that is gaining popularity worldwide to clean up places polluted with petroleum hydrocarbons is known as bioremediation. This study browser the fundamental processes involved in bioremediation and removal efficiency of TPH (Total Petroleum Hydrocarbon) within different periods for (the Baiji refinery) which is polluted with crude oil as a result of numerous oil wells, oil drilling, pipeline, and storage tank damage, natural seepage, and spills during the conflict and Noory channel which content crude oil, waste of refinery process and sludge. The research aims to extract the dominant bacteria in the contaminated soil and use the last in bioremediation and find out the differences in its effectiveness in treating total petroleum hydrocarbons (TPH) later. The result indicates that the dominant bacteria are Stutzerimonas balearica and Bacillus subtilis which are used later in bioremediation and can digest TPH. The removal efficiency of TPH during the study period was 55, 65, 68, 78, 82, 85, and 92% for spilled samples and 50, 62, 66, 70, 80, 84, and 90% for the Noory channel, respectively.