For　laser　welding　with　filler　wire　process,　there　exist　numerous　technical　parameters　about　the　position　between　the　laser　beam　and　the　filler　wire,　so　it　is　difficult　to　guarantee　the　process　stability　and　weld　quality.　In　order　to　obtain　stable　welding　process　and　high　quality　weld,　the　wire　melting　and　transfer　behavior　must　be　controlled　as　the　interaction　between　the　laser　beam　and　filler　wire　is　extremely　complicated.　In　this　work,　laser　welding　with　filler　wire　process　was　studied,　with　particular　attention　to　the　melting　dynamics　of　filler　wire,　the　wire　melting　and　transfer　behavior.　The　high-speed　camera　system　was　used　to　observe　the　wire　melting　and　transfer　behaviors.　The　direct　observation　of　the　welding　process　by　the　high-speed　camera　can　help　to　uncover　the　mechanism　of　the　process　stability　of　laser　welding　with　filler　wire.　Systematic　experiments　were　carried　out　in　this　study　for　liquid　bridge　and　droplet　transfer　mode.　The　results　indicated　that　the　relative　distance　(Wx)　between　the　filler　wire　and　the　laser　beam　and　wire　feed　rate　could　influence　the　wire　melting　and　transfer　behaviors　even　the　whole　welding　stability　significantly.　Therefore,　control　the　Wx　and　wire　feed　rate　is　the　key　to　obtain　stable　transfer　mode　for　the　liquid　bridge.　The　research　findings　provided　a　clearer　understanding　for　improving　process　stability　and　weld　quality.