[Objectives] As a critical strategy of ex-situ conservation, species reintroduction has become a critical approach for rescuing globally endangered species, with its success highly dependent on the sustained reproductive capacity of the target population. This study reported key breeding parameters (including clutch size, hatching rate, and fledging rate) and their variations and identified new threats facing the reintroduced Crested Ibis (Nipponia nippon) population in Ningshan, Shaanxi, aiming to provide a quantitative basis for developing targeted conservation measures. [Methods] We conducted 17 consecutive years (2008–2024) of continuous field monitoring on the reintroduced Crested Ibis population in Ningshan, Shaanxi. Nests were systematically located by observing evening flight directions during the breeding season (February-June) and monitored via binoculars (10 × 42) and spotting scopes (20 ~ 60 ×). We recorded key breeding parameters, including laying date, clutch size, hatching success, and fledging success, and identified the causes of egg losses and chick mortality based on direct observation and physical evidence. For statistical analysis, Welch’s ANOVA was employed to test for annual variations in laying date, while one-way ANOVA was performed to assess annual variations in per-nest hatching and fledging counts. A chi-square test was conducted to analyze the distribution of nests by clutch size. Breeding success metrics (e.g., hatching rate, fledging rate, and reproductive success) were calculated as percentages. All tests were two-tailed, with significance set at P < 0.05. [Results] A total of 222 nests were recorded, producing 723 eggs with a mean clutch size of 3.3 ± 0.9 eggs (range:1 ~ 5 eggs). Specifically, nests with 1 ~ 5 eggs accounted for 4.1%, 14.4%, 35.6%, 43.7%, and 2.3% of the total, respectively, with nests containing 3 or 4 eggs comprising 79.3% of all nests (Table 1). A total of 524 chicks successfully hatched, yielding an overall hatching rate of 72.5%, with no significant annual variation (F_{16, 222} = 0.000 48, P > 0.05). Four hundred nestlings were observed to fledge, resulting in an overall breeding success of 55.3% (Table 2). Notably, fledgling numbers exhibited significant annual differences (F_{16, 222} = 5.820 00, P < 0.01). Major causes of chick mortality included food shortage (45.2%), predation (21.0%), nest abandonment (5.6%), embryo mortality (4.8%) and unknown causes (23.4%) (Fig. 2). [Conclusion] According to these findings, this paper proposes the following conservation measures:(1) establishing an intelligent nest monitoring system to mitigate threats from predators such as the King Rat Snake (Elaphe carinata); (2) developing local economic development plans that fully consider the ecological requirements of the Crested Ibis; (3) implementing a tiered response mechanism of conducting artificial feeding during the brood-rearing stage and winter with food scarcity and activating emergency rescue measures for chicks during extreme climatic events. This study provides a quantitative basis for the scientific management of reintroduction programs for the Crested Ibis and other endangered waterbirds.