Naturally occurring radioactive Radon gas concentrations in the oil-well core as tracer for Naturally Occurring Radioactivity Materials (NORM) were measured in different locations of oil-field in Basra governorate. Two types of Solid State Nuclear Track Detectors were used in the measurements which are CR-39 and LR-115 type-II. The core samples were collected from different depths of ten wells. The number of core samples was 100 which were kept in plastic containers. The maximum radon concentration was 42485 Bq/m3 in well core ID:Ru-277(F2) and minimum concentration was 1223Bq/m3 in well core ID: WQ-31( F6) The arithmetic average radon concentration was 19220 Bq/m3 for maximums and for minimums average was 6504 Bq/m3.