My husband and I are thinking of getting a divorce. We live in Texas ( I have been there for a year and a half), but I am originally from California. I want to know what the laws are regarding moving to California with my son. If I am allowed to do this or not.

Do it in your divorce decree.After your divorce it will be hard...

Yes as part of the child custody agreement and divorce paperwork you will need to have the give permission.

Just to clarify here, its not a matter of laws it's a matter of what you negotiate as part of the divorce. If your ex wants to maintain a relationship and have frequent visitation and custody rights, then it very possible he can block a move since that will make it more difficult for him.