The assembly mechanism of human cytomegalovirus (HCMV) is one of the focal points of research; and the answer to this may provide new targets for intervention. The assembly process consists of two stages. The first stage begins in the cytoplasm where assembly protein precursor (pAP), protease precursor (pPR) and minor capsid protein (mCP) interact with each other and form diverse complexes. The complexes enter into the nucleus and finally form a DNA-containing nucleocapsid. In the second stage, the nucleocapsids will get tegument and envelope. It’s a complicated process involved a variety of proteins and host cells. It’s worth mentioning that structure/function defects of viral proteins may lead to the failure of assembly. The recent researches on the mechanism of assembly of HCMV are reviewed in the present paper.