This paper analyzes the effectiveness of Sino-U.S. governmental law enforcement cooperation to combat human smuggling. A history of bilateral law enforcement cooperation against human smuggling is presented, with emphasis given to the period since 1993. U.S. immigration statistics, along with statistics from the U.S. Coast Guard, are presented as a measure of the success of law enforcement efforts. In the analysis that follows, identification is made of factors that seem to have hindered and obstructed, or promoted and advanced Sino-U.S. law enforcement cooperation. This study finds that sudden shifts in the macroclimate of Sino-U.S. relations may positively or adversely affect cooperation on law enforcement matters, including human smuggling. In the current case, bilateral cooperation against human smuggling has been advanced by spillover effects of convergent Sino-U.S. counterterrorism interests that occurred in the wake of September 11. Next, it is found that the creation of formal bilateral institutions for law enforcement cooperation since 1997 has facilitated improved effectiveness in Sino-U.S. work against human smuggling.. Finally, this study finds that the effectiveness of bilateral law enforcement cooperation against human smuggling has been substantially undermined by the inability of the two sides to maintain an effective repatriation-based deterrent against human smuggling.