HEAT BUDGET IS ONE OF THE MOST IMPORTANT FACTORS IN PHYSICAL STUDY OF SEAS AND OCEANS. DUE TO ITS EFFECT ON ENVIRONMENTAL FACTORS AND LEVELING MARINE STRUCTURES AS WELL AS SEA WATER LEVEL, STUDY OF HEAT BUDGET HAS OF A GREAT IMPORTANCE. STUDYING VARIOUS PARAMETERS INCLUDING THE SUNSHINE ANGEL, CLOUDINESS OF THE SKY, ALBEDO OF WATER SURFACE, AIR SPECIAL HUMIDITY, ATMOSPHERE STRUCTURE, SHORTWAVE SUNSHINE, NET SUNSHINE WITH LONG-WAVE, SENSIBLE HEAT TRANSFER, EVAPORATION HEAT TRANSFER, HEAT TRANSFER BY OCEANIC STREAMS AND RAINING, WIND SPEED, AND LOCAL DIMENSIONLESS (SENSIBLE AND LATENT HEAT FLUX COEFFICIENT), THIS STUDY HAS CALCULATED THE HEAT BUDGET FLUX IN THE BAY ON THE BASIS OF DATA OBTAINED FROM IRANIAN METEOROLOGICAL ORGANIZATION AND THE MOST RECENT FORMULATIONS. THE RESULTS SHOW THAT IN THE YEAR OF 2005, CHABAHAR BAY SAW THE SHORT-WAVE RADIATION FLUX OF (+227.56 W/M2), NET LONG-WAVE FLUX OF (-59.91 W/M2), INSENSIBLE EVAPORATION HEAT FLUX OF (-112.16 W/M2), AND SENSIBLE HEAT FLUX OF (-8.00W/M2). CONSIDERING THE ABOVE MENTIONED PARAMETERS, HEAT BUDGET FLUX IN THIS BAY IS EQUALS TO (+47.49 W/M2). IN ORDER TO ACHIEVE HEAT BALANCE, IT IS REQUIRED THAT SUCH HEAT FLUX EXIT FROM THE BAY THROUGH WATER EXCHANGE BETWEEN OMAN SEA AND CHABAHAR BAY AS WELL AS RAINING.