Abstract: Artemisia annua releases various kinds of allelochemicals into soils via rain leaching, root exudation and dead tissue decomposition during the growing season, with resulting inhibition of the growth and development of adjacent plants and succeeding crops. The present experiments were thus conducted to detect artemisinin derivatives, flavonoids and effects on soil microbes in wild A. annua and surrounding soil. The allelochemical concentrations ranked: bud break period>early flowering period>full bloom period>vegetative growth period (artemisinin in leaves and root zone soil) and stem>leaf>root>flower (flavonoids in plants). In sampled soils, the mean concentration of deoxyartemisinin was highest, followed by artemisic acid and artemisinin in soil and the sum of these artemisinin derivatives was 516.93 μg/kg dry soil. Concentrations of all three compounds tested were highest in root surface soil and much higher in the root surface soil and rhizosphere soil than in non-rhizosphere soil. Soil flavonoid concentrations increased steadily during the growing season of A. annua and reached their highest levels at full-bloom stage (434.77 μg/kg dry soil). Hence it is concluded that flavonoids are released into soils through root exudation. The numbers of bacteria and actinomycetes showed significant negative correlations with artemisinin concentration (r=-0.508^* and -0.478^*, n=24). There was also a negative correlation between deoxyartemsinin contents and actinomycete numbers (r=-0.528^**, n=24). In summary, artemisinin and its derivatives released from A. annua appear to inhibit microbial growth and reproduction, and are therefore likely to influence biochemical reactions in soils.