Atisa's Explanation of Difficult Points in Light on the Path to Awakening (or，in short, Explanation of Difficult Points) is a treatise of the Stages on the Path (lam-rim) genre. It makes easy reading since the emphasis is laid on religious practice，neither strict logical reasoning nor elaborate，profound philosophical systems are dealt with. In order to gain a comprehensive understanding of the text the present paper discusses its editions, the question of authenticity，its special features and impact on Tibetan Buddhism，and those points where Lama Tsongkhapa's Great Stages on the Path differs.
It was found that:
(1) the edition of the Peking Tanjur is not as reliable as that of the Derge Tanjur;
(2) a small portion of the text is probably an interpolation by Nag-tsholo-tsaba based on Atisa's oral explanation;
(3) the concept of "three types of Trainees with differing capacities" was not Atisa's innovation，it can be found already in the Commentary on the Abhidharma-kosa and the Yogacarabhumi;
(4) the peculiar features of Explanation of Difficult Points are (a) the special `Mahayana` refuge on the basis of the general refuge is emphasized, (b) the Bodhisattva precepts are explained primarily in terms of Asanga's Bodhisattvabhumi and secondary in terms of Santideva's siksasamuccaya, while the actual practice of morality stresses both contemplation of illusionary nature and exchanging oneself with others, (c) the practice of meditation stresses supernatural powers which help to accomplish merits quickly, (d) the presentation of wisdom is inclined towards the Prasangika understanding but contains Svatantrika ideas, too, (e) both the `sutra` and tantra traditions of the `Mahayana` are brought together, (f) practice is stressed and more than one hundred scriptures are quoted;
(5) encompassing Indian Buddhism as it flourished then，the text offered Tibetan Buddhism the most correct direction through its combination of practice and teaching，it was also a vital factor which lead to the emphasis on，and later development of，Candrakirti's Prasangika theory in Tibet;
(6) there are six instances where Explanation of Difficult Points and Great Stages on the Path clearly differ，the most interesting of which is that Lama Tsongkhapa moves the treatment of "superior intention" from the section on engaging bodhicitta to the section on aspiring bodhicitta which thus came to constitute "the seven instructions of cause and effect".
