The reforms would make it easier for companies to hire and fire workers, as well as give them more authority over pay and working conditions.
The protesters were trying to make their voice heard, saying the new law is favoring social dumping and weakening the positions of labor unions.
The draft provisions of the labor law have been widely criticized by unions and left-wing parties, as they would make it easier for companies to lay off staff and cut overtime payments. The National Front (FN) party said that the reforms appear to favor large firms rather than small or medium-sized companies.
The French government on August 31 announced the plan to reform labor regulations to give employers more freedom and stimulate the economy. The bill will be submitted to the Council of Ministers of France on Friday.
The French government is also considering moves to outlaw the country's macho culture by making it a criminal offense to harass someone in a workplace, including wolf-whistling.