Sybrina Fulton's comments came during the National Bar Association's annual conference in South Florida, The Miami Herald reported.
"The thing about this law is I just think it assisted the person who killed my son to get away with murder," Fulton said, adding, "I think we have to change these laws so people don't get away with murder."
George Zimmerman, 29, said he fatally shot the17-year-old in a gated community in Sanford on Feb. 26, 2012, in self-defense after the teen attacked him. In a highly controversial ruling, a jury found Zimmerman not guilty on July 13.
The National Bar Association, an organization of African-American lawyers and judges, also called for the repeal of the Stand Your Ground law, which allows people who are in fear for their life or grave harm to use deadly force.
Benjamin Crump, Fulton's attorney, said the law "emboldens" people and leads to needless confrontations.
"We shouldn't call it Stand Your Ground. That sounds dignified," Crump said. "What we should call is it what it is: Make My Day laws," referencing the "Dirty Harry" movies.
Fulton and Tracy Martin, Trayvon Martin's father, are also scheduled to speak at the National Association of Black Journalists conference in Kissimmee Friday, the South Florida Sun Sentinel reported.