Abstract: Bulk skutterudite (FeNi)_xCo_4-xSbl₂ with x varying from 0.05 to 1.0 were prepared by mechanical alloying and spark plasma sintering (MA-SPS). The phases of the samples were analyzed by X-ray diffraction, and their thermoelectrical properties were tested by electrical constant instrument and laser thermal constant instrument. The experimental results show that bulk (FeNi)_xCo_4-xSb₁₂ have the characteristic of typical semiconductor electricity. The addition of FeNi improves the electrical properties to a large extent; the samples of bulk (FeNi)_xCo_4-xSbl₂ (x = 0.05-1.0) are n-type semiconducting materials; the increase of FeNi content can decrease the absolute value of Seebeck coefficient and therefore decrease the ZT value; FeNi with a higher content when x > 0.5 leads to an evident increase in thermal conductivity and also a decrease in ZT value. In general, for ZT value, the optimal added content of FeNi is 0.25-0.5 and the maximum ZT value is 0.2467 when x = 0.5 at 500℃.