Abstract: Abstract: The experimental Chlorella of Chlorella pyrenoidosa FACHB-5 and Chlorella vulgaris FACHB-8 was cultured in a 1 000 mL Erlenmeyer flask with 700 mL nutrient solution in an artificial climate incubator. The culture temperature, illuminance, airflow rate and continuous illumination time were (26±1) ℃, 4 000 lx, 1.5 L/min and 24 h, respectively. The biogas slurry of chicken manure achieved after anaerobic digestion at medium temperature (35 ℃) and high temperature (55 ℃) for 45 d was used as nutrient source for Chlorella culture. The main compositions and characteristics of biogas slurry digested at 35 and 55 ℃ were 2 417.63 and 2 554.37 mg/L for total nitrogen, 2 218.27 and 2 376.24 mg/L for ammonium nitrogen, 16.91 and 13.44 mg/L for total phosphorus, 10 021.82 and 10 104.13 mg/L for chemical oxygen demand (COD), 8.25 and 8.18 for pH value, 698 and 653 NTU for turbidity, and 2.68 and 2.52 mPa·s for viscosity, respectively. The semi-continuous culture of Chlorella was realized by discharging nutrient solution of 10% and adding new nutrient solution of 10% at the same time daily. Furthermore, the addition ratios of unsterilized biogas slurry in daily new nutrient solution were 10%, 20% and 30%, respectively. Effects of 3 different addition ratios of unsterilized biogas slurry digested at 35 and 55 ℃ on the semi-continuous culture of Chlorella were studied systematically based on the analysis of nutrient solution during Chlorella culture including OD680, total nitrogen, ammonium nitrogen, total phosphorus, and so on. The results showed that the Chlorella pyrenoidosa FACHB-5 and Chlorella vulgaris FACHB-8 could adapt the culture environment well and grow rapidly when the addition ratios of unsterilized biogas slurry in daily new nutrient solution were 10% and 20%. Furthermore, the OD680 values of 2 types of Chlorella were maintained at 2.40-2.69 at the end of Chlorella culture for 10 d. However, the growth of FACHB-5 and FACHB-8 in the later period of culture experiment was restrained significantly when the addition ratio of unsterilized biogas slurry in daily new nutrient solution was 30%. Furthermore, the growth rates and adaptive capacity of FACHB-5 in the nutrient solution containing more biogas slurry were better than that of FACHB-8. A similar fluctuation trend was achieved in OD680 of different comparative samples with biogas slurry addition. However, the OD680 values of comparative samples with 55 ℃ digestive biogas slurry were over 0.13 higher than that of comparative samples with 35 ℃ digestive biogas slurry, especially for the comparative samples with biogas slurry of 10% and 20% addition ratios. Moreover, the OD680 values of FACHB-5 and FACHB-8 were maintained at 1.98-2.15 and 1.79-1.92 at the end of Chlorella culture for 10 d, respectively. Therefore, the effects of biogas slurry digested at 55 ℃ on semi-continuous culture of Chlorella were superior than that of biogas slurry digested at 35 ℃. The results supply references for the theoretical research and subsequent large-scale application of Chlorella culture using biogas slurry digested at different temperatures.