In a method of forming carbon nanotubes (CNTs) and a method of manufacturing a field emission display (FED) device using the CNTs, the method includes preparing a substrate on which a silicon layer is formed, sequentially forming a buffer layer and a catalyst metal layer on the silicon layer, partly forming metal silicide domains by diffusion between the silicon layer, the buffer layer and the catalyst metal layer by annealing the substrate, and growing CNTs on a surface of the catalyst metal layer.