His research has been focused on (1) statistical methods for evolutionary genomics for understanding the genome complexity, and (2) high throughput comparative genomics analysis. Achievements of our research group are: Develop statistical methods and bioinformatics software for predicting functional divergence of a protein family, statistical analysis for expression divergence between duplicate genes, and statistical modeling for gene gain and loss during genomic evolution. Analyze across-species model organism genomes, from yeasts, plants, vertebrates to primates. Recently, our research is exploring the new area of Systems Biology and Evolution: Understanding gene pleiotrophy, genetic robustness, genome complexity and gene network evolution.