Research includes finding concentrations of radon (222Rn) and its decay results inside and outside the National Insurance Company building and the surrounding areas,the door of the east-the city of Baghdad for a month,using nuclear track detectors CR-39.The company consists of eight floors,some busy and some deserted.Through the results obtained the value of radon concentrations in the air of all sites of the building at variable rates and was the highest concentration in the ground floor - the basement of the building and was ( 266.999 Bq/m3) and the result is high compared with the limit and there are two reasons for this result first to the lack of ventilation completely in the basement Aoida than to increase the concentrations and secondly increasing concentrations of radon gas in low places and the old and less concentration found on the seventh floor - the secretarial and (27.293 Bq/m3).The concentrations of radon (222Rn) in soil was all results within this limit except the dust that was collected from the dust accumulated on the fourth floor - and the thrusters (171.461 Bq/m3) and where the place is deserted,and with virtually no ventilation.This increase in concentration back to the walls of the building is the main source for the generation of radon inside,it was found that construction materials have played an important role in increasing concentrations of radon inside buildings as well as the old age of the building.