In extension of previous studies the preparation o flow molecular weight amyloses (LMWA) in the range of DP 5-40 was carried out by enzymatic synthesis with either potato phosphorylase or phosphorylase b from rabbit muscle. Interest was focused on the intermediate range of DP 10-20 and on compounds containing a p-nitrophenyl group at the reducing end. Therefore, p-nitrophenyl-α-D-maltopentaoside served as a primer. Investigation of the products by SEC/LALLS and HPLC showed characteristic differences between both phophorylases in the chain length distribution obtained. Whereas the synthesis by muscle phosphorylase leads to an expected Poisson distribution, the synthesis by potato phosphorylase is apparently superposed by a disproportionation reaction. Disproportionation is even stronger with a highly purified enzyme preparation. With both enzymes significant amounts of the desired p-nitrophenyl-α-D-malto-oligosaccharides DP 10-20 can be produced. These oligomers arc of interest for X-ray single crystal diffraction analyses.