In the CIMMYT Maize Germplasm Bank,we have 873 popcorn accessions with ample phenotypic variance.They provide a valuable resource to find the best genetic diversity for popping traits,and to determine the genetic basis for these traits.We have phenotyped 873 landrace accessions plus nine commercial checks for seven traits,including time to first pop,expansion volume,color of endosperm,shape of flake,pericarp remaining after popping,number of unpopped kernels,and weight of unpopped kernels.For time to first pop,157 accessions pop faster than the nine commercial checks.For expansion volume,11 accessions expand to a similar size or larger than commercial checks.Over a quarter of the kernels did not pop in the commercial popcoms,while 39 landrace accessions can pop with less than 5 ％of the kernels remaining unpopped.In conclusion,for every commercially important trait we measured,we identified landrace accessions that were equivalent or even exceeded the commercial checks.We will develop inbred lines to construct an association mapping panel and bi-parental populations to study the genetic basis of popcom traits.