We　report　micrometre-sized　pits　structure,　bump　structure,　and　crater　structure　growth　on　a　Ti　film　surface　by　multipulse　femtosecond　laser　pulses　(λ　=　800nm,　τ　=　30　fs)　irradiation　in　air　at　atmospheric　pressure.　All　the　structures　are　formed　after　0.1s　laser　irradiation　in　our　experiment.　When　laser　power　is　below　20mW,　there　is　no　damage　on　the　film.　A　pits　structure　develops　in　the　centre　of　the　irradiation　spot　after　the　action　of　laser　power　of　22mW,　and　the　depth　is　less　than　10nm.　The　further　increase　of　the　laser　power　leads　gradually　increasing　the　depth　of　the　pits　structure,　which　has　largest　depth　is　70nm　when　laser　power　is　36mW.　When　laser　power　further　increases,　a　bump　structure　is　form　in　the　center　of　the　pits　structure.　The　bump　structure　will　gradually　extend　to　all　the　irradiation　zoon　instead　of　increasing　the　depth　of　the　pits　structure.　The　forming　bump＇s　depth　does　not　exceed　the　thickness　of　the　film.　Until　the　laser　power　is　larger　than　90mW,　a　small　collapse　appeared　in　the　center　of　the　bump　which　leads　to　the　crater　structure.　The　formation　processes　of　these　structures　are　originated　by　the　force　under　different　film　temperature　at　different　laser　power　irradiation,　including　laser　induced　thermal　stress,　plasma　or　evaporation　recoil　pressure　and　surface　tension.　A　simulation　based　on　electron-lattice　two-temperature　model　is　used　to　evaluate　the　temperature　and　the　leading　force　on　the　film　at　different　laser　fluences.