Corrosion behaviour of tin in citric acid, malic acid and glutamic acid at pH 2 and pH 6 in the concentration range of 10""1 M- 10—4 M was investigated. Corrosion potentials were shifted to more negative values with the increasing of citric acid and malic acid concentrations and cor¬rosion rates were increased both at pH 2 and pH 6 Corrosion potentials in glutamic acid at pH 6 were shifted to noble values with increasing of concentration and this was attributed to the film formation. But no regular change between glutamic acid concentration and corrosion rate was observed at pH 2. Order of increasing of corrosion rate of acids were as follows. Citric acid > malic acid > glutamic acid Corrosion rate of tin was increased by the addition of nitrate or nitrite. But accelerating effcct of nitrate and nitrite was pronounced at pH 2. Also accelerating effect of nitrite was found to be greater than nitrate.