IFeature pLine = Temp_Line.GetLayer().FeatureClass.GetFeature(6); IFeature pPoint = Temp_Point.GetLayer().FeatureClass.GetFeature(1); IProximityOperator pProximity = pPoint.Shape as IProximityOperator; double distance = pProximity.ReturnDistance(pLine.Shape);This is all you should do to calculate distance.