With citric acid as chelating agent, ethylene alcohol as etherification agent and water as solvent, NaNbO3 nanopowder was synthesized by citrate sol-gel method. The effects of amount of CA and EG, pH value on the stability of the precursor sol were investigated. The evolution of NaNbO3 crystal phase was also investigated by XRD and TG-DTA. The results showed that a homogeneous precursor sol was formed at in the case of n(CA) : n(metal ion)=3:1, n(CA) : n(EG)=1: 2 and 1:3 and pH=7.5. Sintering process largely influences the morphology of the prepared products. Grain-like nanoparticles could be obtained with a rapid temperature rising rate, while nanorods were obtained with a slow rate. The forming mechanism of different morphologies of the prepared nanoparticles was also discussed.