The present invention relates to a .beta.-catenin oligonucleotide microchip for detecting mutation in the mutational hot spot regions of .beta.-catenin gene, a manufacturing process thereof and a method for detecting the .beta.-catenin mutation employing same, wherein specific oligonucleotides are selectively designed to detect various missense mutations and in-frame deletion at the mutational hot spots of .beta.-catenin gene. The .beta.-catenin oligo chip of the present invention can be used in studies to detect .beta.-catenin mutations and unravel the signal transduction mechanism and tumorigenesis related to .beta.-catenin gene.