The　effects　of　welding　fume　on　welders＇　health　and　the　environment　are　of　great　interest　to　occupational　hygienists　and　welding　consumable　manufactures.　Since　the　welding　fume　sources　from　the　welding　consumables　and　the　flux　core　of　the　wire　is　added　in　many　kinds　of　materials,　the　effect　of　several　kinds　of　adding　materials　on　the　fume　formation　rate　of　lime　titania　type　flux　cored　wire　were　studied.　Research　results　show　that　adding　materials　in　the　flux　core　can　be　classified　into　three　categories:　the　first　kind　can　enhance　the　fume　formation　rate,　the　second　can　lower　the　fume　formation　rate　and　the　third　has　no　effects.　Effects　of　adding　material　content　on　the　fume　formation　rate　are　as　follows:　fume　formation　rate　is　enhanced　by　increasing　the　Na2SiF6　content;　ilmenite　has　no　obvious　effect　on　the　fume　formation　rate;　if　the　core　of　the　wire　is　made　of　right　match　of　metal　powders　and　appropriate　weight　proportion　of　the　feldspar,　the　fume　formation　rate　can　be　greatly　lowered;　the　fume　formation　rate　decreases　in　a　large　scale　if　the　feldspar　content　increases　in　an　appropriate　confine.