http://www.dmv.org/ca-california/point-system.php
actually they changed it now....
As you acquire points, you place yourself in danger of losing your driver's license. The DMV has the right to suspend or revoke your driving privileges if you accumulate a certain number of points over a set period of time.
* Four points within a 12-month period
* Six points in a 24-month period
* Eight points in a 36-month period
Contrary to popular thought, driving records are not automatically cleared of all points once the points are over a year old.