The influences of casting parameters and inclusions on the hydrogen content in 1050 aluminum alloy were studied using optical microscope, scanning electronic microscope and energy dispersive spectroscopy. The results show that with increasing the melt temperature, the environmental humidity and the melt weight, the tendency of hydrogen absorption in 1050 alloy increases. The inclusions in 1050 alloy consist of AlFeSi, Al2O3 and MgO, which always coexist with gas porosity. With increasing the inclusion content, the hydrogen content in Al melt increases. The deep etching method by hot sodium hydroxide employed in this study could evaluate the inclusion content and its distribution more conveniently, quickly and cheaply, is hopeful to be used for site inclusion detection.