The recent advance of study ins cnvilalion nuclei (1980 -1984) is summarized and reviewed, which involved: nuclei models, nuclei measurements, nuclei similarity, nuclei seeding and nuclei effects. All theoretical models about nuclei arc limited in pursuit of establishing a stable structure of free gas in fluid; which are unavoidable in trouble with the nuclei paradox . What is the meaning of ''effective nuclei and inactive nuclei , and how to identify them is still a sophisticated unsolved problem. Both nuc...