A method of preparing a protein chip by gelation of a sol composition. In the method, a mixture of specific silicate monomers, such as SolB1, SolB2 and SolB3, SolBH, and a mixture of SolBS, distilled water and a detector protein are mixed sequentially, so that the gelation rate of the sol composition can be delayed, thus inducing the stable gelation of the composition. Also, the biochip can be fabricated in a simple and easy manner by dispensing the sol composition by hand using an arrayer or a tool such as a pipette. In addition, a uniform biochip can be prepared by dispensing the sol composition, solution I (SolBH) and solution II (a mixture of buffer, SolBS, distilled water and a detector protein) sequentially onto a substrate without needing a conventional pretreatment process such as mixing.