Comparative genomics is an area where the structure and function of genomes of different species are compared. An important goal of comparative genomics is to obtain an insight on how the genomes have evolved. Detection of duplicated regions within species and syntenic regions among species has played an important role in studies of genome evolution. Conserved syntenic regions refer to the regions of chromosome where the gene order and content are the same in different genomes. The conserved syntenic regions help us to infer which regions of chromosome evolved from the same ancestral chromosomes. The comparison of genomes and their contents also allows us to identify genes and other sequence features that are conserved among species and/or genes that are specific to certain clades. These results help us to infer what genes and other sequence features are responsible for the similarities and differences among species. The detection of syntenic regions also has an important practical implication. It allows us to transfer knowledge from well-studied species to less-studied species. Syntenic regions in related species with well-annotated genes can be used to find loci that are responsible for important agronomic traits in the species of interest. In this talk, we will discuss some web-based resources for comparative genomics that can be used in exploring crop genomes.