This study was performed to describe the influence of temperature on the clearance rate and ingestion rate of the blue mussel, Mytilus galloprovincialis with three food organisms and habitat location (shell size) of mussel. Food organisms used in this experiments were Isochrysis galbana, Chaetoceros didymus and Prorocentrum dentatum. The size of mussels inhabiting higher midlittoral zone was smaller than those of lower midlittoral zone. Regardless of the kind of food organisms, filtration rates and ingestion rates of higher midlittoral mussels were higher than those of lower midlittoral mussels in experiment temperature conditions. The variation of filtration rate and ingestion rate showed same tendency with temperature. Filtration rates and ingestion rates increased with temperature, and recorded maximum values at 20-25¡É of temperature, and thereafter decreased gradually. Theoretical optimum temperatures showing maximum filtration rates and ingestion rates estimated from polynomial regression curves were also in the range of 20-25¡É. Blue mussels showed different variation of filtration rate and ingestion rate with the kind of food organisms. Filtration rates and ingestion rate based on cell number were similar regardless of habitat location(tidal elevation) and food organisms. Ingestion rates based on carbon content showed very high values in case of P. dentatum beside I. galbana and C. didymus as food organism.