Abstract： The primary callus formated in induction medium of barley mature embryo cells was watery andsofty. After subculture,secondary callus appeared. It could be classified into several typies such as com-pact embryogenic callus,friable embryogenic and callus and non-embryogenic callus. Embryogenic cal-lus originated from cells of primary callus by somatic embryogenesis and secondary embryogenesis of so-matic embryos. The development of somatic embryo was as same as zygotic embryo. This was mainpathway of plant regeneration from embryogenic cells. Precocious gremination of somatic embryo wasobserved. This paper presented histological studies on the dedifferentiation and redifferentiation parttenof barley mature embryo cells .The microstructure of embryogenic callus and its cell suspensions wereillustrated and compared.