This article reevaluates the Laṅkāvatāra Sūtra in the historyof Chan Buddhism and then examines Master Sheng Yen’s doctrinal take on this scripture. In the first part of this paper,four characteristics of the Laṅkāvatāra Sūtra are discussed: (1)its emphasis on the bodhisattva path; (2) the limits of language;(3) the theory of mind; and (4) features of fifth-century ChineseBuddhism. Along this line, Master Sheng Yen’s understanding of the Laṅkāvatāra Sūtra have at least four relevant themes: (1) the intellectual history; (2) the “two entries and four practices”; (3) the“principal path”; and (4) the “oneness of meditation and wisdom.”In short, Master Sheng Yen’s assessment of the Laṅkāvatāra Sūtra is consistent with previous Chan masters and he insightfully observed that the repositioning of meditation and wisdom marked the watershed in the transition from the “Northern” Chan to the “Southern” Chan Schools.