This paper investigates a combination of Ni acetate solution induced crystallization and microwave induced crystallization of a-Si thin film. Ni acetate solution was coated over amorphous Si thin film for evenly spread of Ni metal source. The Ni inducing source was formed from Ni acetate powder dissolved in de-ionized water or ethanol. The crystallization using Ni acetate solution was a Ni-silicide mediated process, the same process used with Ni metal layer. Compared to Ni metal layer induced crystallization by conventional furnace annealing, it finds that the crystallization temperature was lowered to 450 °C and the time of crystallization was reduced. Using Ni acetate solution induced crystallization is propitious to big area crystallization. After the processing, the poly-Si grain size was found about 0.1-0.5μm. The crystallization of a-Si thin films was enhanced by applying microwaves and Ni acetate solution to the thin films. The technique that combines Ni solution induced crystallization with microwave annealing has potential applications in thin-film transistors (TFT’s) and solar cell.