_{:The effect of flux-cored ingredients and welding parameters on porosity sensitivity of ENiCrMo3T0-4 flux-cored wires were investigated by stereomicroscope and optimum design software. It was found that porosity sensitivity was reduced with the ratio of SiO2/ZrO2,TiO2/ZrO2,and (TiO2+ZrO2+SiO2)/MnO decreased in flux-cored ingredients. The shielding gas flow rate had little influence on number ofneedle holeson weld surface. Big wormhole in weld surface would be formedif flow rate was too low.The number of needle holes and porosity sensitivity of weld metal were the lowest when welding voltage was 25 V, welding current 160 A and wire extension 20 mm.Porosity sensitivity of weld metal can be reduced by enlarging solid-liquid phase temperature and hydrogen solubility in high temperature slag.}