The TMS derivatives of the hydroxyacyldiacylglycerides of sea buckthorn seed oil have been analyzed by mass spectrometry. On the basis of characteristic fragments it has been established that an acyl residue of one of the seven hydroxy acids found previously in hydrolysis products by the GC-MS method is attached in one of the positions of the hydroxyacyldiacylglycerides. The remaining positions are substituted by acyl radicals of the C18:1, C18:2, C18:3 and C18:0 acids. The 24 most probable components of the triglycerides include these acyl and hydroxyacyl substituents. Features of the fragmentation of the components due to presence of polyunsaturated acids have been revealed.