The magnetic and electrical transport properties of La0.5Sr 0.5Co1-xCrxO3(0.05≤x≤0.25) have been studied. We found that Cr-doping leads to the suppression of ferromagnetic(FM) order and metallicity. The zero field-cooled(ZFC) and field-cooled(FC) magnetization displays a broad paramagnetic to ferromagnetic transition at Tc, with a large magnetic irreversibility. The magnetization results indicate that ferromagnetic order changes to antiferromagnetic type with increase of doping concentration. In the metallic samples magnetoresistance peak occurs at Tc but that for insulating sample appears in the lower temperature region far away from Tc. © 2012 American Institute of Physics.