This paper deals with three works on nayatraya “three methods,” namely, śrāvakanaya, pāramitānaya, and mantranaya （i.e., the methods of Hīnayāna, non-tantric Mahāyāna, and tantric Mahāyāna）. The texts establish the essences of the three methods and the superiority of the mantranaya to the other two. The three texts are the Nayatrayapradīpa by Trivikrama （9-10th centry）, the Nayatrayabheda by Kuśalaśrī, and the Nayatrayahṛdaya by an unknown author. They are included in a collection of miscellaneous minor tantric works, a manuscript of which is currently preserved at Norbulingka in Lhasa, and have recently surfaced thanks to a joint research project with Prof. Li Xuezhu. This paper aims to give an overview of these works （i.e., synoptic analysis of each work） and their historical background with special reference to their comprehensive viewpoint that encompasses the whole system of Buddhist doctrines and practices including tantric and non-tantric Buddhisms. As a conclusion, the following points have been clarified: the Nayatrayapradīpa consisting of 20 verses （excluding opening and closing verses） and their prose commentaries focuses on the establishment of the superiority of the mantranaya to the other two nayas; the Nayatrayabheda consisting of 88 verses consisely explains crucial doctrinal topics of the three nayas including pratītyasamutpāda, caturāryasatya, dharmanairātmya, and mantra; and the Nayatrayahṛdaya concentrates on refuting the exsistence of ātman from the viewpoint of the three nayas. The paper also provides the Sanskrit text and its translation of Nayatrayahṛdaya verses 1-7.