Asian seabass is an important aquaculture species in Southeast Asia, Australia and some other countries. The Temasek Life Sciences Lab (TLL) and Marine Aquaculture Center (MAC), AVA have worked on the genetic improvement of Asian seabass in Singapore since 1998. In the past 20 years, we have developed extensive genomic resources and tools for Asian seabass breeding, including the whole genome sequence, mtDNA, a BAC DNA library, transcriptomes from different tissues, high-density linkage maps, DNA markers covering the whole genome, microsatellite and SNP genotyping platforms, statistical platforms for QTL mapping, GWAS, conventional selection and genomic selection (GS). In 2003, we established a founder population of over 500 Asian seabass brooders, which were collected from the wild of four countries, including Indonesia, Thailand, Malaysia and Singapore. After four generations of extensive selection using conventional and molecular breeding approaches, we have established three elite lines, one for quicker growth, and another for disease resistance and the third for higher omega-3 contents. The hybrids generated by crossing different lines are available for commercial production, while the three elite lines are being further selected using DNA markers identified using QTL mapping and GWAS for important traits. Currently, gut microbes are being studies and will be used for selection elite fishes. In this presentation, I will talk about some details of our breeding program.