Aim The elevation of the plasma lipoprotein (a) level is an independent genetic risk factor for atherosclerosis and its major manifestations. The wide variation in lipoprotein (a) plasma levels is ex- plained to a large extent by a remarkable size polymor- phism of the apolipoprotein (a ) isoforms and by u- nidentified sequence variation in the apo (a) gene. A search was made for sequence variants in the 5' flank- ing region of the apo (a) gene and its relation with lipoprotein(a) levels in 85 unrelated healthy subjects ' of Chinese Han Nationality.Methods The plasma concentrations of lipoprotein (a) were measured within one week using a sandwich enzyme linked immunosorbent assay. Pairs of 25- base oligonucleotides were used to amplify sequences -59 to +325 of the apo(a) gene from genomic DNA using polymerase chain reaction (PCR). The PCR- omplified DNA fragments were screened for single rand DNA conformation polymorphism (SSCP) using a modification of the method of Orita. Results one single-strand DNA conformation polymorphism in the apo(a) 5' flanking 384 bp frag-ment was reported. The genotype distribution in 85 healthy unrelated subjects were 0. 812 for genotype 1, 0. 188 for genotype Ⅱ. The mean lipoprotein(a) level in the subjects with genotype Ⅱ was higher than that with genotype I, but the difference did not reach statistical significance. The sequence Polymorphism was not associated with the differences in the plasma concentrations of lipoprotein(a).'Conclusions Sequence variants exist in the apolipoprotein (a) 5' flanking fragment in individuals of Chinese Han Nationality. Though no association was found between the SSCP genotyp and the plas- ma concentrations of lipoprotein (a ), the sequence variants reported here may significantly alter gene ex-pression in vitro.