A petroleum hydrocarbon degrading strain was screened from the soil polluted by petroleum in SongYuan oilfield, and was identified as Stenotrophomonas acidaminiphila strain by 16S rDNA sequence analysis. The effects of material water ratio， drying temperature, carrier ratio were investigated. The results indicated that the petroleum hydrocarbons degradation efficiency was best under the following conditions: water ratio 1:2，drying temperature 35 ℃ and the inoculants on carrier (rice husk, sawdust, diatomite) ratio 80%:10%:10%.