The Six Subtle Dharma Gates (六妙門 Liumiaomen) is one of Zhiyi’s earlier works. It sets forth the Indeterminate Śamatha-vipaśyanā meditation. It is found in the Taishō Tripiṭaka’s forty-sixth volume. Recently, Professor Toshinori Ochiai discovered a version of the Six Subtle Dharma Gates in the Tripiṭaka kept at Nanatsu-dera. Another version is also found in the Zhaocheng Jin Tripiṭaka. Based on the the Nanatsudera and Zhaocheng Jin texts, in this article I will discuss the following two points. First, I will investigate the transmission lineage of the Six Subtle Dharma Gates. Next, I will argue that the Six Subtle Dharma Gates was written before the Sequential Meditative Gates (次第禅門 Cidi Chanmen) and not the other way around as thought earlier. Hence, the order in which the texts discuss the “six subtle dharma gates” meditation is as follows: Six Subtle Dharma Gates, sequential Meditative Gates, Sequence of Dharmadhātu (法界次第 Fajie Cidi) and Profound Meaning of the Lotus Sūtra (法華玄義 Fahua Xuanyi).