Since prehistoric times tar and pitch were very important materials of mankind and therefore can be found on many historical objects. At the place Stillfried/March in lower Austria various objects were excavated with a black probably organic residue. Now the question for the archaeologist was to identify these remains, if they are stemming from pitch and when it is pitch what species of conifer or deciduous trees were used for its production. By means of pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) a variety of findings from the late Umfield period were investigated. In preliminary tests the separation method was optimised, the best conditions for pyrolysis were found and the influence of the matrix on pyrolysis of the birch-tree marker betulin was examined. In the presence of pitches always di- and triterpenes were identified in the pyrograms of the samples. On the surface of some objects other organic materials like foodstuffs were supposed. Moreover by means of principal component analysis within the group of deciduous trees a separation into single clusters for birch, European beech, willow, alder, hornbeam and oak was successful. In fact the conifers of black pine, blue spruce, pine, silver fir and spruce using statistics formed a cluster of their own.