The World Trade Organization ruled in favor of the U.S. that claimed China's use of tariff-rate quotas for rice, wheat and corn limited market access for American grain exports.
The WTO found China had not been transparent, predictable or fair in managing the tariff-rate quotas on U.S. grain exports as the import tax was higher on U.S. grain shipments that exceeded the quota.
The case, started by the Obama administration, marks the second U.S. victory over China this year.
In February, the WTO ruled that China unfairly subsidized its grain producers.