A sample of K465 nickel-base superalloy was prepared by laser solid forming (LSF) technology. The microstructure evolution of grains, γ′ phase and carbides was investigated. It is found that the central region of the sample consists of coarse grains, while the top edge of the sample consists of fine grains. Dendrites in the sample present apparent epitaxial growth along the deposition direction, but the vergens dendrites appear occasionally at the top of several cladding layers near the bottom of the sample due to the inadequate remelting depth. The γ′ particles at the junction of adjacent cladding layers are larger than that inside the layers, and the interdendritic γ′ phase is larger than that at the core of dendrites. MC carbides present variable morphology in the sample, that is, flowerlike at the bottom, short rod-like in the middle and octahedral at the top.