The corrosion behavior of magnetic refrigeration material La(Fe 0.94 Co 0.06 ) 11.7 Si 1.3 in distilled water has been studied using X-ray diffraction analysis, weight loss method, scanning electron microscopy and X-ray photoelectron spectroscopy. Results show that La(Fe 0.94 Co 0.06 ) 11.7 Si 1.3 compound suffers electrochemical preferential corrosion in distilled water. La(Fe 0.94 Co 0.06 ) 11.7 Si 1.3 compound contains three phases which are matrix phase, a small amount of α-Fe phase and La-rich phase. The matrix phase with NaZn 13 structure works as anode to be corroded. The final corrosion products on sample surface are La 2 O 3 , γ-Fe(OOH), Co(OH) 2 and H 2 SiO 3 , respectively. Corrosion has decreased the maximum magnetic entropy change of the compound.