Isozyme are important biochemicalmarkers for studying population ge-netic structure in expediting the sam-pling,evaluation,and use of cropgenetic resource.To identify the ge-netic structure of the rice germplasmin China,we analyzed 6731 cultivarsby starch gel electrophoresis for 12isozyme loci following the proceduresof Glaszmann et al.Fifty-two alleleswere found from the tested materials,which covered 96.3% of the total 54 Isozyme are important biochemicalmarkers for studying population ge-netic structure in expediting the sam-pling, evaluation, and use of crop genetic resource. To identify the ge-netic structure of the rice germplasmin China, analyzed 6731 cultivars by starch gel electrophoresis for 12 isozyme loci following the procedures of Glaszmann et al. Fty-two alleles were found from the tested materials, which covered 96.3% of the total 54