Police say the Thursday night protest was peaceful but when many of the protesters sat in a circle that blocked the street and they refused to disperse, an unlawful assembly was declared.
Police say 54 people were arrested.
Organizers say those arrested included Walmart employees.
The store that opened in September has spurred protests since the planning stages, mostly from labor groups criticizing the company's employment practices.
Wal-Mart spokesman Kory Lundberg says the Walmart employees participating amounts to virtually none of the company's 13,000 employees in LA County. He says those employees know that the company gives them opportunities for career growth and economic security.
