Treatment of PCBs in soil using metallic calcium and alcohol ultimately reduced 1300 x 10(-3)mgkg(-1) PCB concentration to 1.8 x 10(-3)mg kg(-1). Moreover, using the metallic calcium catalyst method to promote the effective use of hydrogen gas in the presence of a specific reducing catalyst such as Rh/C, the decomposition efficiency of PCBs was notably increased despite mild reaction conditions. The total PCB concentration of treated soils decreased from 1300 x 10(-3)mg kg(-1) to 0.62 x 10(-3)mg kg(-1) (decomp. avg.=99.95%). Treatment of soils with metallic calcium and a Rh/C catalyst in alcohol under mild conditions such as 0.15-0.26 MPa at room temperature is extremely effective for degradation of existing PCBs.