Can foreigners fly in China if they have a passport but no visa?

No.

Visa is an endorsement, stamp, or attachment (such as a separate visa) issued by the administrative agency of a country or region on the passport or other travel documents held by citizens of non-citizens of the country or region. To show the procedures for allowing them to enter and exit the country's territory (or go to a third country through its territory).

A visa (Visa) is a permission certificate issued by a country's government agency in accordance with the laws of the country to foreigners who apply to enter, exit or pass through the country.

According to the principles of international law, any sovereign country has the right to decide independently whether to allow foreigners to enter or exit its country, and has the right to issue visas, refuse to issue visas, or revoke already issued visas in accordance with its own laws.

A visa is usually attached to the applicant's passport or other international travel document. In special circumstances, a valid passport or other international travel document may be submitted on a separate sheet. With the advancement of science and technology, some countries have begun to issue electronic visas and biometric visas, which have greatly enhanced the anti-counterfeiting function of visas.

Visa plays an important role in a country’s control of entry and exit personnel, protection of homeland security, and prevention of illegal immigrants and criminals.

A passport is proof of the holder’s nationality and identity, while a visa is a permit issued by a sovereign country to allow foreign citizens or its own citizens to enter or exit the country or pass through the country’s borders.

Visas are generally endorsed on the passport, and some are endorsed on other travel documents that replace the passport. Some also issue separate visas. For example, the immigration visa of the United States and Canada is a piece of A4-sized paper, and Singapore also issues a separate visa to foreigners. Generally speaking, the visa must be used at the same time as the passport to be valid.

A passport is proof of the holder’s nationality and identity, while a visa is a permit issued by a sovereign country to allow foreign citizens or its own citizens to enter or exit the country or pass through the country’s borders.

Visas are generally endorsed on the passport, and some are endorsed on other travel documents that replace the passport. Some also issue separate visas. For example, the immigration visa of the United States and Canada is a piece of A4-sized paper, and Singapore also issues a separate visa to foreigners. Generally speaking, the visa must be used at the same time as the passport to be valid.

Visa is a measure taken by a sovereign country to safeguard its sovereignty, dignity, security and interests. Visa is an important means for a sovereign country to implement entry and exit management of its own borders. If a citizen of a country wishes to travel, settle, trade, study abroad, etc. in other countries, in addition to having a valid passport or travel document, another condition is that he must obtain a visa to the country. Normally, when a country issues visas to foreigners, it is based on the principle of equality and reciprocity in the treatment given to its own nationals by the foreign country, and provides equal preferential treatment and convenience for the nationals of the two countries to travel with each other.