In this research, I reveal that Fabao’s work Yisheng foxing jiujing lun (一乗仏性究竟論), which is famous for criticizing the three vehicle adherents, has consistencies with the Disanjie fofa guaugshi (第三階仏法広釈), a work of an unknown Sanjie-jiao monk of the Tang Dynasty. Further, I point out that the Qiongzha bianhuo lun (窮詐辯惑論) which also belongs to a Sanjie-jiao monk, shows influence that it was written in response to the Chinese Yogācāra.
From this the Sanjie-jiao texts can be understood in relation to the controversy over adherent of the three vehicles and the one vehicle.
