California is a Community Property State.  Under California law, all property acquired during the marriage is presumed to be community property.  If you or your Spouse claim that some property is separate property either one of you owned before the marriage, or acquired during the marriage as separate property, you will have the burden of proving in your Dissolution or Legal Separation case that the property is separate property.  Some of the most important assets in your marriage may be a community property business that you created and built during your Marriage or Domestic Partnership, Investments you managed and controlled during your Marriage or Domestic Partnership, and Retirement or Pension Benefits that you acquired during your marriage.  In any Dissolution of a  Marriage or of a Domestic Partnership, you need to be sure you know all of the assets you own with your partner, and have a clear understanding of whether those assets are community property, or separate property.