Servant of God Matteo Ricci back in the 17th century praised Confucianism for having much natural good in it. He wanted to establish Catholicism in China without destroying in any way the Confucian culture. He sought to embrace and preserve all the elements of Confucianism that were compatible with revealed religion.
It is basically a philosophy of ethical injuctions on personal as well as societal morality, much of which contains sound principles of natural law. There are also certain overtly religious manifestations of it complete with its own rites, such as ancester veneration, I believe.
Its central sacred scripture is the
Analects by Confucius himself. It is very “this-world focused” in that, apart from the ancestor rites which are not really connected to its moral philosophy but are kind of an integral part of old pre-communist Chinese life, it does not teach explicitly about the afterlife or deities.
In the 16th and the 17th centuries, the earliest European arrivals in China, the Jesuits, considered Confucianism to be an ethical system rather than a religion, and one that was compatible with Christianity. The rites, such as the ancestor veneration, were viewed by them as “civil rituals” that could co-exist alongside the spiritual rituals of Catholicism.
At its core is a very humanistic view of reality, based upon good strong family relations and moral leadership.
Catholic Answers has an article on Ricci that you might want to read:
catholic.com/magazine/articles/matteo-ricci-sj
Chinese people have traditionally, I think, had a syncretistic blend of Confucianism, Taoism and Buddhism for their majority religion before Communism was imposed on them by Mao and the revolution of 1949. Confucianist principles are still very important even in modern, Communist China.