Half-Heusler compounds are important high temperature thermoelectric materials having attracted considerable attention in the recent years. However, developing high performance p-type HH compounds with zT>1 has been a big challenge. In this talk, we show that a new p-type HH alloy with a high band degeneracy, Ti doped FeV0.6Nb0.4Sb, can achieve a high zT of 0.8. Increasing Nb content in the Fe(V1-yNby)Sb solid solutions can achieve lower valence band effective mass and consequently higher carrier mobility. Furthermore, increasing Nb content in Fe(V1-yNby)1-xTixSb will also prevent the degradation of the TE performance at high temperatures due to the increased band gap. Thus we obtain a high zT of 1.1 at 1100K for FeNb1-xTixSb without V substitution, which is the highest reported value for p-type HH compounds. In view of abundantly available elements, good stability and high zT, FeNbSb based alloys can be great promising for high temperature power generation.