Cover Story：With the progress of imaging technology, the detection rate of malignant pancreatic cystic including mucinous cystic neoplasm (MCN), intraductal papillary mucinous neoplasm (IPMN), mucinous cystic adenocarcinoma (MCA) have increased, but the distinction between benign and malignant lesions remains a problem. This study is based on the results of surgical pathology and cystic fluid cytology in 35 cases from 120 cases diagnosed by CT or MRI in patients with pancreatic cystic tumor samples. Of the 35 cases, 17 are from the MCN group and 18 are from the serous cystic adenoma (SCN) group. The liquid samples are gained through fine needle biopsy under endoscopic ultrasonography (endoscopic ultrasonography-guided fine needle aspiration, EUS- FNA ). A lectin microarray was used to character the altered glycosylation between MCN and SCN. The t test results show that 6 lectins (STL, WGA, BPL, DBA, PTL-Ⅰ and MAL-Ⅰ) showed different binding signals between two groups (P < 0. 05). Among these, STL, WGA, BPL and DBA exhibited increased binding signals in the MCN cyst (the ratio value > 2.0), which indicated the abundance of Tn antigen in MCN group was higher than that in SCN group. It may correlated with a significant increase in the mucin secretion of cancer epithelial cells. Conversely, the glycopatterns of GalNAcα-1, 3Gal and Galβ-1, 4GlcNAc identified by PTL -Ⅰ and MAL -Ⅰ were decreased in MCN group when compared with SCN group (ratio values < 0.5). In order to investigate precisely alterations of glycopatterns associated with MCN and SCN, SDS-PAGE and lectin blotting analysis was performed with STL and BPL staining. The binding signals of this glycoprotein were significantly higher in MCN than that in SCN groups.