The matching errorof GPSpositioning results and GISdigital mapsin vehicle guidance and monitoring appli cationsare analyzedinthispaper.Accordingtothe errorsources andthe procedure ofdata processing

the matchingerror is divided intofive parts.Itisdetailedinthis paperthe possible errorextents ofthe coarseerror

conventionalerror

and theincorrectcoordinatetransformation and projection methods.The errorprocessing methods are discussed concerningthe stepsrespectively.Furthermore

a map matching methodis putforwardtoimprovethe matching results

andthe effectis discussed .The presented methods minimize the matching error of GPSpositioning and GISdigital mapsin vehicle guid ance and monitoring with the basic hardware platforms available .