TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Microorganisms: The petroleum hydro-carbons degrading bacteria includes newcombe DA, Yu B, Torres LG, Katsivela, E, Rahman KSM, and Das K strains. The epiphyte is Phanerochaete chrysosporium which is of Chinese origin and Cunninghamella which is obtained from oil contaminated soil of crude oil land. The petroleum hydro-carbons decomposing and combining bacterial agent has bacteria or epiphyte chosen from Raza ZA, Das K, Pizzul L, Das M, Bodour AA, Haba E, Crosman JT, and Das K. Preferred Amount: The biomass decomposing bacteria is present in an amount of 108-1012 g/kg biomass, and epiphyte is contained in an amount of 20-100 mg/kg biomass, bacteria enforcing agent and bacterial agent is contained in an amount of 108-1012 g/m2 land, and epiphyte is contained in an amount of 20-150 mg/m2 land. Preferred Plant: The plant includes clover, wheat and paddy.    TECHNOLOGY FOCUS - ENVIRONMENT - Preferred Method: The method involves forcing biomass decomposing bacterial in biomass, uniformly scattering biomass in surface of contaminated soil, processing mechanical tillage to uniformly mix biomass and contaminated soil, forcing water in contaminated soil and keeping the water content between 15-25%, forcing petroleum hydro-carbons decomposition and combining bacterial agents to transform petroleum hydro-carbons, and again processing in situ biological remediation to plants if the consistency of petroleum hydro-carbons is less than 1%. Preferred Components: The biomass decomposing bacterial agent contains bacteria having cellulose degradation property such as Thermoananerobacter, Sporocytophaga, Pseudomonas. The amount of bacteria added for decomposition is 105-1010 cfu/Kg of biomass. The epiphyte includes Phanerochaete chrysosporium of white rot fungi, Trichoderma viride of genus Trichoderma, T.reeaei, T.koningli, or Aspergillus, Aspergillus glaucus, A.niger, and A.terreus, in an amount of 20-100 mg/kg. The bacterium is of Chinese origin. The biomass mainly comprises abandoned straw and saw dust containing lignin and cellulose, in an amount of 3-20% of soil volume. The petroleum hydro-carbons decomposing and combining bacterial agents is at least a bacillus or epiphyte containing the petroleum hydro-carbons degradation capability.