From May 2007 to May 2013,we recorded the 54 died individuals of the Crested Ibis(Nipponia nippon)of a reintroduced population in Ningshan County, Shaanxi Province using banding, radiotelemetry and field surveys. Of the 54 died individuals, there were 26 nestlings, 8 juveniles and 20 released adults. Our results showed that the causes of death of the Crested Ibis included sibling competition, negligence of parents, maldevelopment, predation, shortage of food, flight strike, electrocution of power lines, bad weather, etc. According to the above-mentioned causes, we proposed some reasonable measures of protection and management recommendations.