For the study on the relationship between arterial proteoglycans (PG_s) and atherosclerosis (As), PGs of aortic intima-media of man (from Beijing with higher and Nanning in Guang Xi province with lower prevalence of As), rabbit and dog were separated successively on DEAE-Sephacel ion exchange and gel filtration column chromatography. Three types of PG, namely heparan sulfate PG(HSPG), chondroitin sulfate PG (CSPG) and dermatan sulfate-chondroitin sulfate PG(DSCSPG) were characterized and quantitated. Glycosaminoglycans from DSCSPG were run on cellulose acetate membrane and the relative percentages of DS and CS were calculated densitometrically on stained strips. The results revealed: 1. The contents of total PG,, HSPG and DSCSPG in Nanning sample were significantly higher than the corresponding ones in Beijing sample; 2. The contents of total PG, in aortas of rabbit and dog were lower than that of man, among which the contents and relative percentages of CSPG, HSPG of rabbit and dog, the content of DSCSPG of rabbit were also lower than that of corresponding PG in man; while the DSCSPG content of dog were similar to Nanning man; 3. Lower relative percentages of DS in DSCSPG from Nanning man and dog in comparing with those from either Beijing man or rabbit evne though the content and relative percentage of DSCSPG of Nanning man and dog were higher. As HSPG and DSPG were known to be antiproliferative to arterial Smooth muscl tells and of higher binding affinity to plasma low density lipoprotein respectively, the above results might be implicated in the lower prevalence of As in Nanning man and "resistant" co As of dog.