Using　three-component　acceleration　records　from　222　strong　motion　stations　of　Taiwan　province,　China　and　520　stations　of　Palert　Earthquake　Early　Warning　System,　we　investigate　spatial　variability　and　attenuation　characteristics　of　observed　near-field　strong　ground　motion　during　the　Hualien　M(w)6.　4　earthquake,　and　compare　the　observation　with　NGA-West2　prediction　models.　We　reveal　the　characteristics　of　long-period　motions　during　this　event　and　quantitatively　analyze　the　directional　effects　on　strong　motion　based　on　residual　analysis.　Following　conclusion　can　be　made　based　on　our　study:　(1)　overall　observations　at　PGV　and　long　-period　spectral　accelerations　above　period　1.　0　s　show　good　coincidence　with　the　NGA-West2　prediction　models,　while　the　PGA　observations　and　acceleration　response　spectra　below　period　1.　0　s　are　slightly　lower　than　those　of　the　prediction　models.　Long　-period　motions　above　period　1.　0　s　are　systematically　biased　by　the　azimuth　in　terms　of　spatial　distribution.　In　the　rupture　forward　(South-west　of　epicenter),　observed　spectral　accelerations　above　period　1.　0　s　are　much　higher　than　the　NGA-West2　prediction　models,　while　lower　than　the　NGA-West2　prediction　models　in　the　backward　(North-east　of　epicenter).　(2)　The　rupture　directivity　mainly　affects　the　long　-period　motions　above　period　1.　0　s　and　the　effects　on　PGA　and　short-period　motions　are　relatively　weak.　The　ground　motions　right　ahead　of　the　rupture　forward　at　period　1.　0-10.　0　s　are　strongly　amplified　and　are　1.　16　similar　to　1.　52　times　of　the　average　level.　Observed　ground　motions　in　the　backward　at　period　1.　0　similar　to　10.　0　s　are　reduced　to　0.　36　similar　to　0.　70　times　of　the　average　level.　(3)The　rupture　directivity　during　the　Hualien　earthquake　shows　clear　narrow-band　effect.　The　influence　of　the　rupture　directivity　including　the　amplification　effects　in　the　forward　and　de-amplification　effects　in　the　backward　reaches　its　maximum　values　at　the　period　T=3.　0　s.　The　maximum　amplification　and　de-amplification　coefficients　are　1.　52　and　0.　36　respectively.　From　the　period　3.　0　s　to　10.　0　s,　the　influence　of　rupture　directivity　gradually　weakens　with　the　increase　of　period　on　the　whole,　which　is　significantly　different　from　the　characteristics　of　the　rupture　directivity　effects　during　the　2016　Kumamoto　M-W　7.　0　earthquake　in　Japan.