There has been a long controversy over the factors determining caste fate of individuals in social insects. Recent studies of genomic imprinting show that genes can be differentially marked in egg and sperm and inheritance of these epigenetic marks cause genes to be expressed in a parental-origin-specific manner in the offspring. It has been known that parental phenotypes influence the caste fate of offspring in termites. For example, female offspring of sexually matured queens and worker-derived males develop exclusively into queens, as do parthenogenetically produced daughters. Recently, we demonstrated that parental phenotypes influence the social status of the offspring not through genetic inheritance but through genomic imprinting. Here we show that age of king influences the caste fate of offspring and DNA methylation level changes as king’s age. We also show that alate sex ratio can be also explained by the sexual maturity of kings and queens. In this talk, we highlight the current theoretical and empirical evidence for genomic imprinting in termites and discuss how genomic imprinting acts in caste determination and social behavior and challenges for future studies.