Among the Tangut Buddhist texts discovered from Khara-Khoto, there emerges a text entitled Gu tsja & Gamma;iej tsji r tshji kji.j, which means 'Analysis of the Essence of Madhyamaka.' Intriguingly, a Tibetan treatise com-posed by Rgya dmar ba Byang chub grags (fl. 12th century) bears the same title. A comparison between the texts in both languages shows that about 50% of their contents are the same. Although the Tangut text can-not be regarded as a translation of the Tibetan text we see today, the complex relationship between both texts and the history of the transmission of the Tibetan treatise is worth investigating.