BaTa(O,N)3 nano-powder was fabricated within minutes with urea as nitrogen source and pressure-less spark plasma sintering technique as a calcination tool. The effects of urea content, heating rate, synthesis temperature and dwell time on the purity of the products were studied and optimized. Experimental results show that excessive urea and proper synthesis temperature benefit the synthesis reaction. The purity of BaTa(O,N)3 powder can be significantly improved by applying a higher heating rate and an intermediate dwell time. Based on the processing optimization of 8 times molar(urea content), 300℃/min(heating rate), 1000℃(synthesis temperature) and 0~1min(dwell time), the obtained BaTa(O,N)3 powder possesses an average particle size of 50~150nm, a uniform Ba/Ta/O/N element as well as a good purity.