Abstract: Abstract: Honeybee is a typical social insect specie. Honeybees have the common characteristics of insect, also have unique characteristics. One of the unique characteristics is caste differentiation. Queen and work all develop from zygote. But they switch into two different castes with different physiological and morphology characteristics from same genome. The queens are in large body size, long life-span and fertile, while the workers are in small body size, short life-span and nearly sterile. What have caused these changes ,a number of studies have been conducted on the differences between honeybee workers and queens to solve the secret. This review will recap the caste differentiation from five aspects of nutrition, hormones, DNA methylation, differential gene and protein expression .Furthermore, high light unanswered questions in need of further research.