In this paper, GaN quasi-periodic nanopillars were fabricated and investigated. The quasi-periodic nanopillars were realized by nanoimprint technique and selective area growth. Localized lasing mode was identified in the GaN quasi-periodic nanopillars. The threshold energy density and lasing wavelength were 40 mJ/cm2 and 369 nm, respectively. The divergence angle and near-field lasing spot were measured to be 10.5° and 3.6 μm, respectively. The spontaneous emission coupling factor of localized lasing mode was estimated to be 9.4 × 10-3. The mode patterns in the real and reciprocal spaces were calculated by the multiple scattering method to confirm the mode localization behavior.