Abstract: The effect of aluminium on the pore sensitivity,microstructure,mechanical properties and inclusion of the deposited metal were studied by changing the amount of aluminium powder in the flux core and the aluminium content in the steel sheath of the self-shielded flux-cored wire.The results show that with the increasing amount of the aluminium powder in the flux core of the wire,the content of oxygen and nitrogen in deposited metal and pore sensitivity of weld reduce obviously,but the content of aluminium and amount of inclusion in the deposited metal increase,and the microstructre of deposited metal is deteriorated seriously,the toughness of the deposited metal goes down.When using the aluminium contained steel sheath,the harmf of aluminum to the properties of deposited metal can be limited to some extent.