Tiantai sect (天台宗), also known as Fahua sect (法華宗), is one of the sects of Chinese Buddhism, which began in the late Northern and Southern Dynasties. It is called Tiantai Sect because of its founder, Zhiyi 智顗, who lived and taught the Buddhist teachings in Tiantai Mountain, Zhejiang Province. With The Lotus Sutra of Wondrous Dharma as its fundamental classic, it is also known as the Fahua Sect. Because this sect focuses on the practice of shamatha-vipassana meditation, it is also called the sect of meditation. Because it attaches great importance to the study of Buddhist teachings and combines the actual practice of shamatha and vipassana, it is famous for “the double beauty of teaching and vigilance”.

Tiantai Sect takes the Lotus Sutra of Wondrous Dharma as its purpose, the Great Perfection of Wisdom Treatise (Dazhi dulun, 大智度论) as the guide, the Great Nirvana Sutra (Da niepan jing, 大般涅盘经) as the support and explanation, and the Great Prajna Sutra (Da bore jing, 大般若經) as the method of contemplation. Zhiyi’s Tiantai three classics, namely Fahua wenju (法华文句), Fahua xuanyi (法华玄义), Mohe zhiguan (摩诃止观) are the foundation of the sect. Zhiyi made the teachings of the Buddha’s time into five times and eight teachings. The five times are the “Huayan” time, the “Ahan” time, the “Fangdeng” time, the “Bore” time, and the “Fahua Niepan” time.

Tiantai Sect is one of the earliest sects in Chinese Buddhism. It gathers the doctrines of righteousness and Chan 禪 from various schools in the north and the south. And it organizes and develops them into a system. It was supported and believed by the court and the folks at that time, and it had a great influence on the various schools established after the Sui and Tang Dynasties. After the Yuan and Ming Dynasties, scholars of this sect often advocated the Pure Land, and formed a style of “teaching and performing Tiantai, returning to the practice of Pure Land” (教演天台，行归净土). Although the Tiantai sect has risen and fallen several times in China, it still continues to this day.

At the beginning of the 9th century, the Japanese monk Mozumi introduced this sect to Japan. During the Heian period (784-1192), it developed side by side with Shingon, and was historically known as the two Heian sects. In the 13th century, the Nichiren sect was separated from this sect. Today, the Tendai Honshu and Nichiren sects in Japan are very prosperous, and in the 20th century, Nichiren sects split into several new sects.

The main practice methods of Tiantai sect are the meditation practice of shamatha and vipassana and the Tiantai repentance method. Shamatha and vipassana: shamatha means concentration, vipassana refers to wisdom, and therefore, shamatha-vipassana meditation is the practice of concentration and wisdom. The Tiantai repentance method refers to the repentance method of Fahua Samadhi, repentance of Fangdeng, the repentance of Golden Light Sutra, and the repentance of envoking Avalokitesvara. At the same time, the Tiantai Repentance Method also established the systematic model of the repentance practice in Chinese Buddhism.