The　characteristics　and　function　of　geographic　information　system　(GIS)　technique　were　summarized　and　the　advantages　of　GIS　application　in　environmental　impact　assessment　(EIA)　were　introduced.　GIS　can　provide　good　function　of　information　technology　for　EIA,　based　on　its　strong　ability　on　processing　spatial　data　and　attribute　data.　The　applications　of　GIS　in　establishing　environmental　information　database,　selecting　sites　for　projects,　making　environmental　thematic　map　and　combining　with　environmental　model　to　predict　environmental　impact　were　introduced.　The　traffic　noise　prediction　of　Beijing　Xiwai　Street　west　extension　project　in　EIA　report　was　taken　as　an　example　to　introduce　GIS　application　in　urban　road　EIA.　©　(2013)　Trans　Tech　Publications,　Switzerland.