A carbon modified NaTaO3 mesocrystal nanoparticle (ca. 20 nm) was successfully synthesized by a one-pot solvothermal method, employing TaCl5 and NaOH as the starting materials and distilled water/EG mixed solution as a reaction solvent in the presence of appropriate amounts of glucose. The mesocrystal sample presented a high specific surface area 90.8 m2 g-1 with large amounts of well-dispersed mesopores in the particle, owing to the co-effect of EG and glucose during the reaction process. A non-classic mechanism of formation was proposed for the growth of the NaTaO3 mesocrystal. Furthermore, the NaTaO3 mesocrystal exhibited considerably improved visible light absorption in addition to the intrinsic UV light absorption as a result of carbon modification originated from glucose. On the basis of the large specific surface area, high crystallinity and optical property, the carbon modified NaTaO3 mesocrystal demonstrated excellent efficiency for continuous NO gas destruction under irradiation of UV, short wavelength visible lights (>400 m) and even long wavelength visible light (>510 nm), considerably superior to those of the unmodified NaTaO3 specimen and commercial titania, P25. The carbon modified NaTaO3 mesocrystal nanoparticles prepared in this work would probably have potential utilization in environmental purification and energy conversion.