According to police in the city of Xuzhou, they arrested included seven teachers and nine foreign students. The police did not provide details of the specific nationalities of the arrested or the type of drug used.
In a statement on their social media, English-language education provider Education First (EF) said with "deep regret" that some of their teachers had been involved in drug use.
CNN has come out to the EC for comments. The British Foreign Ministry could not confirm whether the two cases were related or when the British were arrested.
"We are in contact with the Chinese authorities after the arrest of four British people in Jiangsu Province and are providing consular assistance, "said the State Department in a statement.
The Chinese government has little tolerance for the use or trade of illegal drugs in the country. Anyone who is in more than 50 grams of a controlled substance can face the death penalty.
In recent years, authorities in major Chinese cities have intensified their efforts to crack down on recreational drug use, including drug testing at bars and nightclubs.
According to the Xuzhou police, a foreigner was under criminal detention while the other 18 suspects were under "administrative detention".
EF said it would immediately terminate employment contracts with all employees who were confirmed to have used illegal drugs in China.