The thyroid hormone responsive spot 14alpha (THRSPalpha) gene plays important roles in chicken growth and fat deposition. The aim of this study was to identify new variations in the gene to determine their effects on growth and fat traits in chicken and to observe the effects of the THRSPalpha gene on chicken lipid profile and lipoprotein and glucose and triiodothyronine effects on the THRSPalpha expression in liver and fat cells. Two new variations, namely A197835978G and G197836086A, and a reported 9-bp insertion-deletion (indel) of the THRSPalpha gene were genotyped by single-stranded conformational polymorphism in a Xinghua x White Recessive Rock F(2) full-sib resource population. The results showed that the A197835978G was significantly associated with hatch weight and BW at 28 d of age and breast muscle weight at 90 d of age in chickens (P < 0.05). The G197836086A was significantly associated with cingular fat width (P = 0.0349) and breast muscle crude fat content (P = 0.0349). The indel was significantly associated with abdominal fat weight (P = 0.0445). The above new THRSPalpha polymorphisms were also significantly associated with the total cholesterol and low-density lipoprotein, in which the THRSPalpha GA/AG genotype was associated with lipid and lipoprotein and the THRSPalpha BB indel genotype was significantly associated with liver weight in chicken breeds. The mRNA expression analysis in vivo and in vitro culture studies suggested that the THRSPalpha gene is more responsive to glucose than triiodothyronine. In conclusion, the 3 variations of the chicken THRSPalpha gene were associated with both growth and fat traits in this study. Such effects of the THRSPalpha gene were further supported from the data of observations in association analysis of the gene with phenotypic records and plasma lipid profiles, in the THRSPalpha gene expression in chicken development, and in vivo and in vitro cell culture observation of liver and abdominal fat tissues.