The State Administration for Market Regulation, China's top market regulator, stipulated that businesses shall not sell blind boxes to juveniles under 8 years old,
as part of broader efforts to regulate the country's billion-dollar blind box industry.
A blind box is a popular way of packaging toys and other products to keep their contents hidden.
The Chinese Academy of Social Sciences estimated that the market size of China's trendy toys, mainly including blind boxes, is expected to hit 47.8 billion yuan ($7.06 billion) this year.
According to the guideline, which is open to public opinion on the SAMR's website on Tuesday,
businesses can only sell blind boxes to those aged 8 and above after obtaining the consent of their guardians.
The guideline said companies shall not bid up prices and should reasonably determine prices of blind boxes based on production and operation costs as well as market supply and demand.
Prices of blind box products should not have a big gap from that of non-blind box products of the same quality, it said.
In January, the China Consumers Association said that blind box consumption is expanding in a disorderly manner, from pets to air tickets,
and increasing problems are also arising, including illegal sales, unknown probabilities and consumption addiction.
China Media Group reported a case in which a blind box was priced at 800 yuan but the actual cost was only about 30 yuan.
Some consumers spend more than 10,000 yuan to buy blind boxes in order to get a limited-edition toy.
As some business operators sold blind boxes with pets inside,
the SAMR draft guideline also clarified that live animals, drugs, medical devices, special cosmetics and unmarked express parcels cannot be sold in the form of blind boxes.
Following the news, Pop Mart, Chinese mainland's leading blind box company, started with a slight drop but closed with a 3.3 percent increase in share price on the Hong Kong stock exchange.
在该规定发布后，中国内地领先的盲盒公司Pop Mart在香港证券交易所开盘小幅下跌，但收盘时股价上涨3.3% 。
The company said in a statement that the draft guideline is of positive significance and can offer clear directions to companies to operate in a standardized way, which helps the sector create a better business environment.