The specific time required for each chemotherapy treatment for gastric cancer is related to the chosen chemotherapy regimen, and the number of days of treatment varies with the chosen chemotherapy regimen. The commonly used FOLFOX regimen is oxaliplatin combined with calcium folinic acid and fluorouracil intravenous chemotherapy, which usually takes 3 days to complete the whole chemotherapy, and 14 days is 1 cycle. In contrast, oxaliplatin combined with capecitabine regimen, oxaliplatin is administered intravenously on day 1, while capecitabine requires 14 consecutive days of oral administration with a 1-week break, with 1 cycle every 21 days. The regimen of docetaxel combined with cisplatin and fluorouracil usually takes 5 days to complete 1 cycle of chemotherapy and 1 cycle of 28 days. Therefore, the exact duration of each course of chemotherapy for gastric cancer is determined by the chosen chemotherapy regimen. Different conditions will choose different chemotherapy regimens, so patients should consult their doctors to develop a suitable chemotherapy regimen according to their specific conditions. Gastric cancer chemotherapy is also divided into pre-operative neoadjuvant chemotherapy, post-operative adjuvant chemotherapy and palliative chemotherapy. Pre-operative neoadjuvant chemotherapy is generally evaluated for 2-4 cycles, while post-operative adjuvant chemotherapy is generally required for 6-8 cycles, while palliative chemotherapy should be judged by clinicians during the course of chemotherapy according to the patient’s efficacy and tolerance level.