Abstract: Objective To explore the pioneering symptoms of the gastrointestinal symptom cluster and their influencing factors in gastric cancer patients with chemotherapy. Methods Based on the hospital's management system for scientific research data, 463 gastric cancer patients with chemotherapy were surveyed through multicenter collaboration by the corresponding module of the MD Anderson Symptom Inventory (MDASI), the Chinese Medicine Constitution Classification and Identification Standard, and the Chinese Medicine SyndromeIdentification Standard for Gastric Cancer. IBM SPSS Statistic 22.0 and IBM SPSS Modeler 18.0 were used for data analysis. Results The first occurrence of dry mouth in the gastrointestinal symptom cluster of gastric cancer patients with chemotherapy was (22.99±10.70) hours after chemotherapy. The support, confidence, and lift for the association between dry mouth and decreased appetite were 62.2%, 94.8% and 1.52, respectively; for dry mouth and nausea, the numerical values were 62.2%, 89.6% and 1.44; for dry mouth and vomiting, the numerical values were 62.2%, 79.5% and 1.28. The results of one-way ANOVA and multivariate linear regression analysis showed that alcohol consumption, syndrome of stomach heat injuring yin, and phlegm-dampness constitution were independent influencing factors for dry mouth in gastric cancer patients with chemotherapy (P<0.05). Conclusion Dry mouth, as a pioneering symptom of the gastrointestinal symptom cluster, is of great significance in clinical assessment and management. Improved assessment of dry mouth can provide a basis for the construction of subsequent risk prediction model, the formulation of targeted interventions, and the enhancement of symptom management efficiency.