Although in Croatia there are favourable environmental conditions for common bean (Phaseolus vulgaris L.) cultivation, the fact is that this culture is neglected in our country and the area under beans is insufficient. Phaseolin is the major storage protein of the common bean and it consists of complex heterogeneous glycoproteins with different composition of a polypeptide encoded by a gene family. Research was carried out on isolation of phaseolin using specific PCR primers with which is possible to multiply the sequence of genes phaseolin, analyse the differences in the pattern of amplified fragments and determine the type of phaseolin. Research included 107 accessions of Croatian common bean landrace 'Trešnjevac' originated from different counties of Croatia. All of the accessions of common bean landrace 'Trešnjevac' have the Andean origin. Most of the accessions (72,90 %), from all of the Counties, had phaseolin type III ("T"), while only one third of the accessions had phaseolin type II ("H" or "C"). The exception is Krapinsko-zagorska County in which the most of accessions had phaseolin type II (H or C). Accessions with climbing growth habit had phaseolin type II ("H" or "C") while accessions with determinate bush habit had phaseolin type III ("T").