Using the thermal activity monitor(TAM) air isothermal microcalorimeter,the heat flow power (HFP)-time curves of splenic lymphocytes growth at 37°C were measured,and the effects of crude Radix Aconiti Lateralis(Fuzi) and its processed products including Yanfuzi,Danfuzi,Baifupian on splenic lymphocytes growth were investigated by microcalorimetry coupled with principal component analysis (PCA).Some quantitative information,such as growth rate constant k,maximum heat-output power Pmax,appearance time for the highest peak tmax,the heat output for the log phase Qlog,the total heat production Qtotal for all the metabolic progress of mice splenic lymphocytes,were obtained from the HFP4ime curves to present the effects of crude Radix Aconiti Lateralis(Fuzi) and its processed products on splenic lymphocytes growth.By analyzing these quantitative parameters using PCA,the effects of crude Radix Aconiti Lateralis(Fuzi) and its processed products on mice splenic lymphocytes growth were quickly evaluated from the change of the main parameters(k and Pmax).The results revealed that crude Radix Aconiti Lateralis(Fuzi) and Yanfuzi had inhibitory effect on mice splenic lymphoeytes growth:crude Radix Aconiti Lateralis(Fuzi) with half-inhibitory concentration (IC50) of 18 mg.mL-1 showed stronger inhibitory effect on splenic lymphocytes growth than Yanfuzi with the IC5o was 32 mg·mL-1.Mean while,Danfuzi and Baifupian promoted splenic lymphocytes growth:Baifupian with the median effective concentration (EC50) of 25 mg·mL-1 showed a little stronger promotion effect than Danfuzi with ECh0 of 28 mg·mL-1.This study indicates that we could get toxicity information of Radix Aconiti Lateralis(Fuzi) directly by analyzing parameters of microcalorimetry and evaluate different bioeffects of crude Radix Aconiti Lateralis(Fuzi) and its processing products on splenic lymphocytes growth.