We studied how gastric cancer tissues and cells changed as a result of preoperative chemotherapy. 82 patients with gastric cancer in TNM I-IV stage underwent preoperative selective vascular chemotherapy with routine quantity of FAM. Histological analysis of their postoperative specimens revealed the following results. (1) Cancer tissues necrosed in 56.1% patients. These necroses, due to the chemotherapy, were located around vascular vessels. (2) Cancer cells were found to change with karyopyknosis, karyorrhexis, coagulation and necrosis of cytoplasm. There were invasion of lymphocytes, inflammation edema, and fibroelastosis around cancer cells as well. Changes were also observed in vessels with proliferous intima and thrombus. Most of these changes were grade 2. This paper summarises that preoperative vascular chemotherapy can bring about evident histological and cell changes in different types of gastric cancer. This kind of chemotherapy is recommended as one of integrative treatments to gastric cancer.