Abstract: The present invention relates to test strips and preparation method thereof. More particularly, the present invention relates to a test strip comprising: (a) an insulating substrate; (b) an electrode system disposed on the insulating substrate; (c) an insulation layer disposed on the electrode system, in which an accommodation space is disposed at one side of the insulation layer for exposing a part of the electrode system to carry out an electrochemical reaction of an analyte; and (d) a gel, disposed in the accommodation space and formed by dissolving a reactive enzyme reacting with the analyte in a hydrogel and being cured.