It is an object of the present invention to provide an immunochromatography method capable of measuring a sample in a low concentration range and a high concentration range by setting the measurable range of the sample much wider than the conventional measurable range. The present invention provides an immunochromatography method, which comprises: spreading a test substance, a first labeling substance modified with a first binding substance that binds to the test substance, and a second labeling substance modified with the first binding substance that binds to the test substance, which are in a mixed state, on an insoluble carrier; and capturing the test substance, the first labeling substance, and/or the second labeling substance at a reaction site on the insoluble carrier having a substance having ability to bind to the first binding substance that binds to the test substance, so as to detect the test substance, wherein the first labeling substance is a labeling substance that causes an amplification reaction, and the second labeling substance is a labeling substance that does not substantially influence on the amplification reaction.