The spectrum of NIII has been studied in the region of 2000-680? by using a two meter normal incidence vacuum spectrograph and a condensed discharge as light source. Experimental results indicate the evident effect of the pressure of light source on the appearance of NIII spectral lines. Thirty-one new spectral lines are observed. A new energy level, 2s2p4d2D5/2, is found, and the energy value of the level 2s2p4d2D3/2 is revised.