Abstract: After twenty years of Chernobyl accident, the international conference was hold in Kyiv, Ukraine, 24-26, April in 2006. During the conference WHO declares the paper named health effects of the Chernobyl accident. The report look back the nuclear accident in the history, and then recite conclusion about health effects of the Chernobyl accident, which from doses received from the Chernobyl accident, thyroid cancer, non-thyroid solid cancer, leukemia, mortality, cataract and cardiovascular disease. The report is considered as milestone events in the studying of health effects of Chernobyl accident.