To explore whether big individuals can affect small individuals' growth for cuttlefish Sepia pharaonis under the stress of social hierarchy, this study was conducted indoors in small cages (Φ=60 cm, h=20 cm), and the survival rate, specific growth rate, oxygen consumption rate, ammonia excretion rate and metabolic enzyme (ATP enzyme, pyruvate kinase and hexokinase) changes were measured after 40 days of cultivation, to analyze the effects of different body sizes (large size L:body weight of 4 to 5 g, middle size M:body weight of 2.5 to 3.5 g, small size S:body weight of 1 to 2 g, with separate cultivation and mixed cultivation (LMS ratio 1:1:1), using single factor design. The results showed that:the L S. pharaonis' special growth rate was not significantly different between separate cultivation and mixed cultivation, but the growth rates of groups M and S S. pharaonis' were significantly lower with separate cultivation, specific growth rates for each group were LMS-M (3.12±0.35)%/d, M (5.21±0.24)%/d, LMS-S(1.39±0.28)%/d and S (4.37±0.42)%/d; after 10 days of cultivation, the survival rates of S. pharaonis were not significantly different between separate cultivation or mixed cultivation, but after 20 days of cultivation, the survival rate of mixing cultivation was significantly lower than that of separate cultivation; after 40 days, the survival rate for each group were LMS(41%±5.35%), M(60%±4.58%), L(61%±6.43%) and S (63%±5.57%). The oxygen consumption rate showed no significant difference for separate cultivation and mixed cultivation, but groups M and S with mixing cultivation oxygen consumption rate was lower than the single standard breeding groups M and S S. pharaonis' oxygen consumption rate, oxygen consumption rate in each group were LMS-M[(0.48±0.03) mg/(g·h)], M[(0.69±0.02) mg/(g·h)], LMS-S[(0.75±0.04) mg/(g·h)], S[(0.94±0.04) mg/(g·h)]; L S. pharaonis' ammonia excretion rate showed no significant difference under seperate cultivation and mixed cultivation, but the ammonia excretion rates of mixed cultivation of groups M and S were lower than the single standard breeding groups M and S S. pharaonis' oxygen consumption rates, ammonia excretion rates in each group were LMS-M[(0.057±0.004) mg/(g·h)], M[(0.082±0.007) mg/(g·h)], LMS-S[(0.085±0.007) mg/(g·h)], S[(0.135±0.007) mg/(g·h)]; L S. pharaonis' ATP enzyme, pyruvate enzyme and hexokinase activities showed no significant difference between separate cultivation and mixed cultivation, but mixing cultivation of groups M and S, S. pharaonis' ATP enzyme, pyruvate kinase and hexokinase activity were lower than the single standard breeding group M and S S. pharaonis' oxygen consumption rate, ATP enzyme activity in each group were LMS-M[(1.25±0.16)U/mg prot], M[(2.74±0.26) U/mg prot], LMS-S[(0.77±0.11) U/mg prot], S[(1.94±0.09) U/mg prot]; pyruvate kinase activity in each group were HET-M[(51.14±6.24) U/mg prot], M[(78.05±8.38) U/mg prot], LMS-S[(27.94±6.65) U/mg prot], S[(55.92±2.81) U/mg prot]; hexokinase activity in each group were LMS-M[(10.71±1.24) U/mg prot], M[(23.59±1.67) U/mg prot], LMS-S[(5.91±0.83) U/mg prot], S[(13.82±1.66) U/mg prot]. Thus, L S. pharaonis have a significant impact on the normal growth rates of M and S S. pharaonis under mixed cultivation, which is bad for cuttlefish farming.