In current study blood indices of Yellowfin Seabream, Acanthopagrus latus, were measured in order to investigate patterns of response and to quantify the extent of alterations caused by the mercury pollution. During the environmental exposure of mercury pollution in five creeks of Persian Gulf some blood characteristics were examined. Mercury concentrations were determined using a standard cold vapor atomic absorption. Numbers of Blood leukocytes and leukocyte differential count were counted under the light microscope. Hematocrit readings were performed with microhematocrit reader. Hemoglobin were determined colorimetrically. Serum glucose and total protein were measured photometrically. The range of mercury concentrations founded in the creeks water and specially sediments along the Mahshahr coast was higher than other marine environment. It was declared that MCHC; leukocyte count, neutrophil lymphocyte and total protein can consider as biomarker of mercury pollution in yellowfin seabream.