There is provided a method of manufacturing a zirconia block for an artificial tooth having a color gradient. The method includes: preparing colored zirconia-based powder and white zirconia-based powder; preparing a plurality of raw materials in which the colored zirconia-based powder and the white zirconia-based powder are mixed in different weight ratios by mixing the colored zirconia-based powder and the white zirconia-based powder while changing a mixing ratio in order to express a desired color gradient; sequentially injecting the plurality of raw materials into a compression mold or a mold frame to mold in increasing or decreasing order of content of the colored zirconia-based powder of the raw material; and calcining a molding result. According to the present invention, it is possible to express aesthetics of a natural tooth by implementing a color gradient of the natural tooth in the zirconia block itself without using porcelain powder or a liquid color set.