The American shad (Alosa sapidissima) is an anadromous fish species with ecological importance along the east coast of North America. At present, it has a potential for aquaculture in China because of its commercial importance and high market value. To evaluate and compare the growth regularity and difference of young fish A. sapidissima cultured in outdoor and shaded ponds, the standard length and body mass of young fish A. sapidissima (n=600) cultured in outdoor and shaded ponds were measured. The results showed:The relationship of body length and mass of young fish cultured in outdoor and shaded ponds could be described by the power function (W=aL^b, R²>0.99, P<0.01,n=300), the values b were close to and slightly less than 3 (2.786 4 and 2.843 1, respectively), and the body length grew slightly faster than the body mass. A leap-style compensatory growth reaction was found in young fish at the beginning of the culture experiment (0-15 d), and then the body length and mass specific growth rates (SGR) of young fish steadily declined with increasing culture time. The relationships between the body length of young fish cultured in outdoor and shaded ponds and culture time could be described by the linear function (L=at + b, R²>0.97, P<0.01, n=9), the intersection point of two straight lines appeared at 73.25 d (September 29); Nevertheless, the relationships between the body mass and culture time could be described by the quadratic function (W=at²+bt+ c, R²>0.97, P<0.01, n=9), the intersection point of two curves appeared at 61.92 d (September 18); at the earlier stage of culture experiment, before 57 d (September 13), young fish of outdoor pond grew faster than shaded pond; at the later stage, after 79 d (October 5), the reverse is true. The food coefficient of outdoor pond (1.22) was lower than that of shaded pond (2.04). The coefficient of variations of young fish body length and mass in outdoor pond was smaller than that of shaded pond. Therefore, the adaptive capacity for high temperature of young fish A. sapidissima is better than adult fish. It is suggested that:the young fish A. sapidissima should be cultured in outdoor pond, and then adult fish should be cultured in shaded pond.