This invention relates to a method for gastric cancer diagnosis through the detection of glycan changes, and to a kit for gastric cancer diagnosis. More specifically, based on the fact that in gastric cancer patient-derived haptoglobin, there are changes in N-linked glycosylation of haptoglobin, which are detected through lectin and mass spectrometery, that is, an increase in fucosylation, increases or significant changes in specific glycan structures depending on the classification of antennary structures, or a remarkable decrease in a high mannose structure of the N-glycan as compared to normal persons, N-glycan structures identified using the changes in N-linked glycosylation of haptoglobin may be usefully used as a diagnosis marker in a method for gastric cancer diagnosis using lectin or mass spectrometry, and a kit for gastric cancer diagnosis.