problem installing pyserial

Hi, i'm trying to install pyserial on osx lion.
when i launch install from terminal i have this error:

MacBook-Pro-di-Gabri:pyserial-2.5 Gabri$ python setup.py install
running install
running build
running build_py
running build_scripts
running install_lib
creating /Library/Python/2.7/site-packages/serial
error: could not create '/Library/Python/2.7/site-packages/serial': Permission denied
MacBook-Pro-di-Gabri:pyserial-2.5 Gabri$

what can i do to enable permission to create the folder?

tx

Gabriele

ok, done typing:

sudo python setup.py install