Considering　the　problem　of　a　false　modal　and　the　decision　of　a　real　IMF　in　an　improved　Empirical　Mode　Decomposition　(EMD)　by　using　frequency-band　filters,　a　signal　analysis　method　based　on　the　combination　of　improved　EMD　and　Independent　Component　Analysis　(ICA)　was　proposed.　This　proposed　method　does　not　require　setting　a　threshold　in　advance,　and　the　real　IMF　component　can　be　isolated　automatically.　This　method　also　can　eliminated　the　false　modal　components,　which　appeared　in　the　process　of　an　improved　EMD,　thusly　it　can　make　sure　the　validity　of　an　EMD　very　well.　Afterwards,　the　random　decrement　technique　(RDT)　is　used　to　obtain　free　vibration　modes　of　each　IMF.　Finally,　Hilbert　Transform　(HT)　and　the　least　square　fitting　are　employed　to　identify　structural　modal　parameters　from　these　free　vibration　modes.　Finally,　the　presented　method　is　used　to　identify　modal　parameters　of　two　numerical　examples　and　a　seven-story　steel　frame.　The　results　show　that　the　proposed　method　can　resolve　the　drawbacks　of　an　improved　EMD　more　effectively,　and　the　modal　parameters　can　be　identified　successfully.