Abstract: Molysite is introduced into releasing agent and with the increasing sensitivity of molysite , a method for determination of ultra trace gold in rock samples by graphite furnace atomic absorption spectrometry is introduced . Detction limit of the method is 0.02 ng/g with precision of 5%~8% RSD n=12 . The method is accurate and reliable . Through the test of first grade national standard reference materials, the result meets the quality demand and is in agreement with certified values .