Though the law of the anti-Mafia-like criminal group (LACG) plays a important role in struggling against the underworld and ruffians in China, there are some questions both in theory and judicial practice, which even affect the blow to LACG.

The present thesis aims at analyzing the differences and similarities between the underworld and the organizations with traits of the underworld from the aspect of "having known" and "attend", so as to help identify them correctly and punish them severely.

Over the past few years,the organizations with traits of the underworld have shown the tendency towards perfection in their structure,the diversification of means,and political infiltration.

The forming and development of the underworld organizations is regular.

The organized crime with Gang nature is a conceptual category that differs from Gang s crime and organized crime as well as has connections with them.

Economic factor is the material base on which an organized gangsterdom relies for survival and development.

The author believes that the organization crime in the nature of criminal syndicate and underworld crime are the same except in the level of organization.