Methods of mercury measurements in blood are rather different; however the most common is cold vapor atomic absorption spectrometry, though there are other methods of use, such as mass-spectrometry with ICP as ion source and activation analysis. Whole blood is an object with difficult matrix composition, so micro elemental measurements require prerequisite sample treatment that increases the time spent on analysis and there is a danger of losing the analyte. Thus, the creation of direct method of Mercury measurement in blood is actual problem. In this paper we developed the methodology of direct Mercury measurement in whole blood using GFAAS. This work was carried out using atomic absorption spectrometer MGA-915; we used high frequency nonelectrode Mercury lamp as source of radiation (wavelength 254.7). As a result of work we suggested optimal conditions of Hg GFAAS measurement - optimal temperature-temporal program of heating of graphite oven, permanent surface modifiers and oxidation modifiers were suggeste