Glancing angle deposition (GLAD) is a powerful and versatile nanofabrication technique to produce nanorod arrays with different shape, size, composition, and heterostructures. Usually GLAD is used to fabricate nanostructures from single component materials or compound materials; however, composite nanostructures are another important nanomaterial that have tunable properties and many important applications. While nanocomposites have been produced extensively by different chemical synthesis methods, they have not been achieved by GLAD. In this dissertation, we demonstrate the fabrication of composite nanostructures with tuning material composition/property by co-deposition GLAD for both photocatalysts and plasmonics. First, we introduce a novel high throughput combinatorial fabrication of nanomaterial libraries through a co-deposition GLAD process. This process results from the spatial distributions of vapors for two deposition crucibles and is demonstrated with the fabrication of CuxFeyOz composites. Both Fe2O3 and CuxO have been extensively studied as visible light driven photocatalysts due to their small band gaps, and the mixture of Fe2O3 and CuxO results in better electron and hole separation and reduction of free electron recombination, which could improve their photocatalytic performance. Then, different composite BixWOy nanostructures are fabricated through co-deposition and annealing to improve the performances of both photocatalytic dye degradation and photoelectrochemical water splitting. The ideal BixWOy composites show zero bias water splitting at a photocurrent density of 0.35 A cm-2 and a maximum density of 4.3A cm-2 at 600 mV as well as relatively high dye degradation rates. Last, nanotriangle arrays of Ag and MgF2 mixtures are fabricated by a combination of nanosphere lithography and co-deposition. Based on the effective medium theory, the principle of sensitivity of localized surface plasmon resonance sensor, and the optimized deposition conditions, we show an improved sensitivity from 312 to 698 nm/RIU when the Ag composition in Ag-MgF2 nanotriangles is about 90 at.% compared to that of the pure Ag nanotriangles with the same size and thickness. Overall, the co-GLAD is a powerful fabrication technique in high throughput nanomaterials screening, nanomaterial optimization, and many applications. The examples demonstrated in this thesis are only very limited results and applications for this technique. More advanced nanomaterials design and applications are expected.