Proximate compositions, TVB-N and mineral compositions of dark and light muscle of bonito were investigated. Results showed that moisture and lipid contents of light and dark muscle were significantly different in both muscles. Dark muscle of bonito contains high amount of lipid whereas light muscle contains elevated level of moisture. However, protein and ash contents of both muscles did not show any differences. Although the fish were at the same freshness level, the amount of TVB-N was much higher in dark muscle (37.5 mg N/100g) than light muscle (22.4 mg N/100g ). Although no significant differences (P>0.05) were found in the levels of Cu, Mn, Pb, P and Zn level, remaining K, Fe, Na, Ca and Mg levels showed significantly different (P0.05) in both muscle type. While iron and calcium were high in dark muscle, sodium, potassium and magnesium were high level in light muscle.