Oligomeric copolymers of dimethyl siloxane and l,l,l-trifluoropropylmethyl siloxane having functional amine groups at both ends were prepared and their microstructures were analysed by n.m.r. spectroscopic techniques. The compositions of these polymers were obtained by integration of the corresponding peaks of H-1 n.m.r. spectra, while the monomer triad sequences were calculated from the regions with the aid of curve fitting. Being oligomers, the polymers contain a significant amount of end groups, and the peak positions corresponding to the end units that are contributing to the regions were determined by two-dimensional H-1 COSY spectroscopy. The compositions of the polymers were found to be almost equal to the feed ratios, and the monomer sequence distributions appeared to follow the Bernoullian statistics.