Recent detection of benzene by Cassini's INMS at 1200 km altitude of Titan's atmosphere (Wait et al., 2005) suggests that complex organic chemistry may occur in the upper atmosphere of Titan. This study attempts to understand the role of EUV-VUV light in the subsequent complex organic chemistry. The formation of gaseous species from N2/CH4 gas mixtures as a function of EUV-VUV irradiation wavelengths from 50 nm to 150 nm is investigated. A N2/CH4 (= 95/5) gas mixture at 0.066 mbar in a 1 m length windowless photocell is irradiated by VUV light using a synchrotron radiation source at the Advanced Light Source. The photon wavelength can be controlled from 50 nm to 150 nm with a ~1 nm bandwidth. The gaseous species produced by photochemistry are analyzed using a quadrupole mass spectrometer. The formation of heavy organics up to C8 to C10 by EUV light irradiation is observed, and the gas products depend on the irradiation wavelength. In particular, the efficient formation of benzene and toluene is observed during the irradiation at wavelengths less than 80 nm. This suggests that the photoionization of nitrogen may initiate the formation of benzene via ion-molecule reactions. In the N2 dominant atmosphere of Titan, the extreme ultraviolet radiation may play an important role in activating complex organic chemistry of the upper atmosphere through the photoionization of N2 molecules. We acknowledge the support by the NASA exobiology grant (NNG05GO58G).