thank you very much BPFowler.
I did not installed wx-widget and so i forgot to export the path for include and libs. Your shell commands were right.

But i have another error. I think it will be more easier to fix it since it comes from my configuration, i guess :

In file included from .././wxOil/pngfiltr.h:104,
from prvwflt.h:110,
from bitfilt.cpp:118:
.././wxOil/outptpng.h:109:17: error: png.h: No such file or directory
.././wxOil/outptpng.h:166: error: 'png_structp' does not name a type
.././wxOil/outptpng.h:167: error: 'png_infop' does not name a type

the libpng is installed. I have the png.h file in /sw/include/libpng12/
There is also one in the SRC folder of Wx-Mac's folder.

Do you have any ideas ?

thanks