Abstract: The developments of body size and digestive organ size in wild tadpoles of Mongolian toads (Pseudepidalea raddei) during the Gosner stages 28, 38, 42, 44, 45, and 46 (G28, G38, G42, G44, G45, and G46) were recorded following Gosner staging table (Gosner, 1960). Blood samples were collected by cutting tail or cardiac puncture. The percentages of different subtypes of leukocyte and the ratio of neutrophils to lymphocytes (ratio of N/L) were measured. The results showed that body mass, total body length, and tail length initially increased, and then gradually decreased over the developmental stages. Body length and the ratio of body mass to body length were increased over all the developmental stages. The length and wet mass of small intestine reached the peak in G38, with the wet mass being higher than that in G42. Liver wet mass increased from G28 to G45 tadpoles, but decreased in G46. Percentage of neutrophils in G45 was greater than in G38. Percentage of eosinophils was greater in G44 than that in G42 and G45. Percentages of lymphocytes, basophils and monocytes, as well as the ratio of N/L did not change across different developmental stages. These results indicate that the sizes of energy acquisition and energystorage organs reach the maximum value at metamorphic peak and before landing, respectively. The changes of the proportions of neutrophils and eosinophils are beneficial to the transition from aquatic to terrestrial environment, as well as to the completion of metamorphosis development.

Key words: photosynthetic capacity, Changbai Mountain, Korean pine and broad-leaved forest, seasonal dynamic., canopy crane