This experiment was carried out in pot culture test,by using three-factor completely randomized design and plate culture count to measure the number of soil bacteria,actinomyces and fungus sampled at different time.This research studied the influences when adding carbamide and under 2,4-D stress on soil microbes,which revealed the dynamic changes of soil bacteria,actinomyces and fungus when adding carbamide and under 2,4-D stress.The results showed that significant inhabitation to growth of soil bacteria were found from one to sixty days under high-concentration 2,4-D stress,but for actinomyces and fungus stimulation at first then inhibition later,three bacteria didn′t recovery to the level of control until 60th day;However,under low-concentration 2,4-D stress,inhibiting effects appeared to all these three bacteria from 1 to 60 days.So it is concluded that adding carbamide and could stimulate the reproduction of bacteria,actinomyces and fungus,and stimulating effects to the three bacteria of mixed 2,4-D and carbamide or mixed 2,4-D and carbamide and were more significant,Compared with the control,the stimulating effects to bacteria and actinomyces were significant at 0.01 level,the average highest activation rate reached 396.5 percent and 125.9 percent from 1 to 60 days.