Hi Janne, you are right ...the headers is the only we need ...with the right definition of function calls in C# thanks for the reply -- View this message in context: http://osgeo-org.1803224.n2.nabble.com/Import-Proj-native-library-in-C-tp6589496p6592203.html Sent from the PROJ.4 mailing list archive at Nabble.com.