III-nitride semiconductors have drawn considerable attentions for its wide success in photonic devices including light-emitting diodes, laser diodes, solar cells, and photodetectors. In addition to discrete devices, recent studies on III-nitride waveguides have now opened up new opportunities in integrated photonics for biochemical sensing, beam steering, nonlinear optics, and quantum photonics applications in the UV and visible spectral region. For example, due to their wide bandgap, low material dispersion, and active integration capability, III-nitride materials are particularly attractive for integrated nonlinear optics applications, including second harmonic generation, comb generation, and parametric down conversion. In this talk, I will first present our recent studies on the fundamental nonlinear optical properties of GaN, namely, two photon absorption coefficient, three photon absorption coefficient, and Kerr nonlinear refractive index, and discuss their impacts on the device performance. I will also discuss on-going research at ASU on AlN nanophotonic ring resonators for second order harmonic generation of picosecond UV coherence light, as well as supercontinuum generation from UV to IR. The presented III-nitride integrated photonics platform would enable a wide rangeof applications in biochemical sensing, quantum information, and optical communications.