In order to study the decomposition process of rice straw in upland soil and the effect of three stalkdegradable microbial preparations,two pot experiments and one field trail were conducted by measuring ratio of straw weight loss (RW),straw cellulose degradation (RCD) and hemicellulose degradation (RHCD).The tested microbial preparations were SDA,SDB and SDC.It was showed that decomposition process of rice straw in upland soil could be regarded as four stages: initial stage,early degradation stage,middle degradation stage and late degradation stage according to RW.Stalkdegradable microbial preparation could significantly promote straw degradation rate in initial stage,and environmental temperature had great impact on straw degradation particularly to that with inoculating microbes.In the initial stage,it took 10 days in green house under 20℃with three stalkdegradable microbial preparations applied,which was 15 days earlier than CK treatment.For the field test below 10℃,SDB and SDA treatments took 45 days in the initial stage,while CK treatment spent 60 days.Compared with SDB and SDA,SDC showed no effect on rice straw decomposition in this field test.