The　Chi-Chi　earthquake　firstly　supplied　us　unprecedented　near　fault　recordings　and　made　it　possible　to　study　deeply　the　characteristics　of　near　fault　ground　motion.　However,　there　are　considerable　offsets　of　baseline　of　the　near　fault　accelerograms　obtained　in　this　event.　The　reasons　of　the　offset　of　baseline　are　more　complex　than　those　occurred　in　other　near　field　recordings　with　farther　fault　distance.　Therefore,　general　baseline　correction　schemes　for　near　field　recordings,　such　as　the　methods　of　BAP　(Converse,　1992)　and　Iwan　(Iwan　et　al.,　1985),　could　not　be　used　directly　in　baseline　correction　of　this　event,　as　pointed　out　by　Boore　(1999).　As　far　as　our　information　goes,　no　robust　procedure　for　the　correction　of　baseline　offsets　that　can　be　applied　to　near　fault　digital　recording　of　this　event　has　been　proposed.　This　has　hampered　to　a　considerable　degree　the　further　studies　on　the　near　fault　ground　motion　of　this　event.　To　develop　such　a　procedure,　the　specific　sources　of　the　baseline　offsets　must　be　understood.　Basing　on　the　result　of　our　systematical　analyses,　we　propose　that　the　tilt　of　instruments　due　to　differential　settlement　of　the　materials　in　the　vicinity　of　the　instrument　should　primarily　be　responsible　for　the　large　baseline-offset　occurred　in　the　near　fault　recordings　of　this　event.　A　baseline　correction　scheme　for　the　offsets　caused　by　the　tilt　of　eccelerograph　is　put　forward　in　this　paper,　which　could　eliminate　the　offsets　of　baseline　effectively.　It　is　noted　that　a　low-cut　filter　can　eliminate　the　effects　of　the　baseline　offsets,　but　it　may　cause　the　loss　of　information　about　the　permanent　displacement.　The　method　given　by　the　authors　in　this　paper　does　not　involve　any　filter,　so　that　we　can　get　the　permanent　displacements　from　the　double-integrated　accelerograms,　which　coincide　well　with　the　co-seismic　displacements　measured　by　GPS　instruments.　Accroding　to　the　study,　the　offsets　of　baseline　have　fairly　small　effects　on　PGA　and　response　spectra　within　the　period　of　0.1　to　6　second,　which　is　of　great　interest　to　engineering　circle.　However,　PGV,　PGD　and　D-last　are　strongly　effected　by　the　problem　of　baseline　offset.　Therefore,　the　baseline　correction　of　near　fault　ground　motion　recordings　is　of　great　importance.　The　method　of　baseline　correction　proposed　in　this　paper　can　be　applied　to　the　near　fault　ground　motion　recordings　of　the　1999　Turkey　and　Chi-chi　earthquakes.