An experiment was carried out during kharif season of 2009 It consisted of thirteen treatment combinations comprising of two phosphorus levels (20 and 40 kg P2O5 ha-1), three phosphorus sources (DAP, SSP and PROM), two biofertilizers (PSB and Rhizobium) and one absolute control. The experiment was conducted in factorial randomized block design and it was replicated three times. To evaluate the effect of phosphorus sources, levels and biofertilizers on black gram. Among the different sources of phosphorus DAP produce significantly higher pods plant-1(46.02), grain pods-1 (8.20), 1000 grain weight (40.63gm) and seed weight pod-1 (0.83gm), seed (10.20 q ha-1), haulm (21.40 q ha-1) and biological(31.61 q ha-1) yields. Further, DAP also recorded highest net returns (Rs. 25112.60 ha-1) with benefit cost ratio of 2.77. Similar trend also observed in case of phosphorus levels. Application of 40 kg P2O5 ha-1 gave significantly higher yield attributes, seed (10.65 q ha-1), haulm (23.00 q ha-1),biological (33.66 q ha-1) yields, net returns (Rs. 26315.54 ha-1) and benefit cost ratio (2.80) over 20 kg P2O5 ha-1 and control. Seed inoculation with PSB markedly enhanced yield attributes, seed yield, (10.11 q ha-1), haulm (20.88 q ha-1), biological (30.98 q ha-1) yields net return (Rs 24529.87 ha-1) with benefit cost ratio 2.65 over Rhizobium and control of black gram. With regards to interaction effects application of 40 kg P2O5 though DAP along with PSB brought significant effect on seed yield on Black gram.