Alloy composition, depositing conditions and annealing procedures are important factors affecting thin-film properties. In order to select suitable materials for resistive films, microstructures of NiCr-O and Cr-Si sputtered films used for the mid-range of resistance were analyzed. Electrical properties of the films before and after annealing were compared. The possibility of degradation was examined by short-time test. The results show that, after annealing, microstructure of Cr-Si sputtered film is nanometers' chromium silicides embedded in amorphous matrix and SiOx, while NiCr-O sputtered film is a mixture of Cr2O3 and atomic short-range order metallic phases. Cr-Si resistive film is tighter and more stable than NiCr-O resistive film, and the former has the advantageous electrical properties to resist puncture voltage and damp.