The four-day patrol covered 512km with seven vessels and 187 law enforcement officials taking part.
A total of 12 vessels, 25 people and 8.5 tonnes of cargo were inspected during the mission.
The joint patrols first started in December 2011 after a gang hijacked two cargo ships and killed 13 Chinese sailors in Thai waters.
Nearly 13,000 officers and 680 vessels have so far joined the past 80 missions, contributing to cracking down on crimes.
The Mekong River is a vital waterway for cross-border shipping among China, Laos, Myanmar, Thailand, Cambodia and Vietnam.
