Abstract: The biosynthesis of ergometrine through the use of the ergot fungus Claviceps microcephala has been applied to the manufacturing of this alkaloid. By thin layer chromatography, it has been shown that this strain, cultured on wheat seed medium, was able to produce three other ergot alkaloids besides ergometrine. In order to fully utilise the alkaloids in the mother liquor, obtained during the production of ergometrine, and to gain information on the mechanism of biosynthesis, it was necessary to isolate and identify these ergot alkaloids. With the application of preparative-scale thin layer chromatography without binder, four alkaloids were isolated from the mother liquor. In addition to ergometrine, the three others were identified as ergometrinine, ergosine and ergosinine respectively, by their thin layer chromatographic behavior, melting points, optical rotations, U.V.and I.R.spectra and elementary analyses.