Four weeks’ domestication Carduelis flammea were selected to test the effects of photoperiod on their body weight, organ mass, basal metabolic rate, body fat mass fraction, debranching enzyme activity and other physiological and biochemical indicators. Three treatments were prepared, they were long light group (12 hours of light and 12 hours of dark), short light group (8 hours of light and 16 hours of dark) and the control group. The results showed that: 1) After domestication, Carduelis flammea body weight in short light group increased 1.05 g, body mass reached very significant level compared to the control group (P<0.01), while it did not get great increase in long light group before the1–3 weeks’ acclimatization; 2) Basal metabolic rate in short light group in 2–4 weeks got obvious increase with amount of 0.38 mL/(g?h), while after domestication at 3 weeks, basal metabolic rate in short light group reached very significant level compared to it in long light group (P<0.01), at the end of 4 weeks of acclimation, it reached very significant level in short light group compared with the long light group (P<0.01); 3) Debranching enzyme activity in muscle in the short light group reached significant level compared to them in the long light group and control group (P<0.01), as well as it in liver in the long light group compared to the short light group and control group (P<0.01); 4) Body fat mass fraction in short light group was higher 2.19% than that in control group, while it was lower 1.73% than that in control group in long light group; body fat mass fraction in short light and long group reached very significant level compared to the control group (P<0.01), it reached very significant level in the short light group compared to that in the long light group (P<0.01); 5) Digestible energy in long light group was respective higher 22.71 kJ/g and 24.69 kJ/g than them in short light group and control group, it reached very significant level in long light group compared with it in the short light and control group (P<0.01); 6) The fresh weight of heart, stomach, kidney and pancrea in short and long light group were not reached very significant level compared them with the control group (P>0.05). Photoperiod was one of the main environmental factors affecting the change of thermogenesis at the condition of short light, Carduelis flammea could adapt itself to the change of photoperiod by improving body weight, basal metabolic rate, debranching enzyme activity in liver and muscle tissues to compensate the energy consumption from a series of physiological and biochemical reactions.