The Liumiaomen 六妙門 was preached by Zhiyi 智顗 and positioned as a work that clarifies the buding zhiguan 不定止観 （indeterminate cessation and contemplation meditation）. This paper compares the contents of the Liumiaomen with other works of Zhiyi. As a result, a new significance of the Liumiaomen was revealed. I point out that it is necessary to examine whether the assignment of the Liumiaomen to the buding zhiguan is really due to the intention of Zhiyi.
