Enchin (円珍, 814-890) wrote a commentary on Vasubandhu's Miao-fa lian-hua jing you-po-ti-she (妙法蓮華経憂婆提舎, *Saddharmapu?darīkasūtropade?a) entitled Hokkeron-ki (法華論記), in which he brought forward a large number of citations from various works. But not a few of them still remain to be identified. This paper is an attempt to give solutions for some particular instances of this kind. 1. There are two passages by "Ji-de" (寂徳). Both of them are most probably from the Fa-hua-lun shu-ji (法華論術記) by Yi-ji (義寂) and Yi-yi (義一). 2. "Sengaku" (先覺) is mentioned fifteen times in all. There is good reason to believe that the famous scholar Ji (基) is meant thereby, and that those passages attributed to "Sengaku" are from his Fa-hua xuan-zan (法華玄賛). If we add them to what are already known to be citations from it, the Fa-hua xuan-zan proves to be one of the most frequently cited works in the Hokkeron-ki. 3. Although "Ci-en" (慈恩) usually refers to Ji (基), this is not always true of the Hokkeron-ki. There are some instances in which "Ci-en", seems to denote a commentator on the Fa-hua yi-shu (法華義疏) of Ji-zang (吉蔵). The same is the case with "Jin-gong" (進公), whose statements cited in the Hokkeron-ki also seem to have been taken from a commentary on it. According to several catalogues of books introduced from China, Enchin brought the commentary by Dao-jing (道進); there are no other commentaries on the Fa hua yi-shu which we can say for certain that Enchin introduced to Japan. Therefore, it is very probable that not only "Jin-gong" but also "Ci-en" in the above cases is no other than Daojing, whose commentary Niao-fa liars-hua jing chao (妙法蓮華経鈔) are quoted under those names in the Hokkeron ki. In this connection it is interesting to note that citations from the Fa-hua yi-shu itself are relatively few and very brief. Why is this so? This question seems to be answered by saying that they are not directly from the original but indirectly through that commentary, because Enchin could not obtain the original Fa-hua yi-shu according to the relevant catalogues. 4. In the Hokkeron-ki Enchin cites the Fa-hua yi-zuan (法華義纉) of Zhi-du (智度) with considerable frequency, whereas he never mentions any of those works by disciples or followers of Zhan-ran (湛然), to which he often refers in his other treatises than the Hokkeron-ki. However, this does not necessarily indicate his higher estimation of the Fa-hua yi-zuan. In the present writer's view, it is simply because the other works were not accessible to Enchin when he wrote the Hokkeron ki. 5. There is one passage which seems to be extracted from the Daijō sanron daigi-shō (大乗三論大義鈔) of Gen'ei (玄叡). It is not certain, however, whether he really quotes it or refers to some other unknown work that constitutes a common source on which Gen'ei also relies. 6. Enchin brought various Abhidharma treatises from China, including Ju-she-lun song shu (倶舎論頌疏) of Yuan-hui (円暉) and the Ju-she-lun song shu ji (倶舎論頌疏記) of Dun-lin (遁麟). According to Prof. H. Sakurabe, it was Chūsan (仲算, 935-976) who quoted the former for the first time in the history of Japanese Buddhism, but the fact is that both of the above two were already cited in the Hokkeron-ki. The paper concludes with the following remarks. To have a proper understand-ing of the character of the Hokkeron-ki in terms of its manners of quotation, it is sometimes important to consider which books were available to Enchin and which were not, because the absence of quotation from a book X in it may be explained by X's inaccessibility to the author. At any rate, the present study has confirmed to a considerable extent that the Hokkeron-ki is full of reference to and criticism of the Fa-xiang (Hossō) school (法相宗). Still more attention should be paid to this aspect for a future study.