Brown signed the legislation Wednesday morning at the Ronald Reagan State Building in Los Angeles.
The reforms include a cap on annual pension payments for new public employees, hired after Jan. 1, 2013. The changes also require new employees to contribute at least half of their pension costs.
Under the plan, new employees will have an increased minimum retirement age and cap the annual payout at $132, 120. It will also eliminate numerous abuses of the system and require workers who are not contributing half of their retirement costs to pay more.
The state's public pension system is under funded by about $150 billon.
The Associated Press contributed to this report.