1.5×106 CFU/dry soil atrazine-degrading strain Arthrobacter sp. AG1 was inoculated into three different types of soils (yellow-brown soil, fluvo-aquic soil and red soil) with atrazine (AT) at the concentration of 50 mg/kg. AT decreased to 1.5, 6.6 and 10 mg/kg. respectively in the three kinds of soils by AG1 after 10 days. AG1 degraded AT efficiently in these soils and the degrading efficiency was affected by soil characteristics. AG1 could still degrade AT in acid soil, even when soil pH was lower than the lowest pH for its growth. After removing AT in soils, AG1 could remain its degrading ability for long term even if soil water content was adjusted to 5% and 15%. After 60 days, AG1 inoculated before could still degrade over 65% of the 50 mg/kg AT which was added to yellow-brown soil and fluvo-aquic soil secondary. Low soil water content and pH value were not suitable for AG1 survival and pesticide-biodegradation in soil. Degradation was affected by soil water content, the feasible water content for AG1 to degrade AT efficiently should be above 20%. Degradation was also affected by inoculation volume, however, 105 to107 CFU/g dry soil inoculation volume could degrade AT efficiency.