The indoor and outdoor radon measurements in Haerbin and Yanan have been made with CSR detectors. At main measuring sites the balloon method has been used to measure the latent energy of daughters and the equilibrium factor. The results by the two methods have been compared and analysed. The measurements with CSR detectors indicate that the indoor radon concentration ranges from 16 to 144 Bq/m3 with an average of 73Bq/m3 in Haerbin

while from 13 to 78 Bq/m3 with an average of 35 Bq/m3 in Yanan. The results are compared with those with the balloon method

showing that the two methods are consistent within an error of 40%.