Mitoxantrone Hydrochloride Injection for Tracing (MHI), a modified new drug marketed in China, has been approved by the National Medical Products Administration for lymph node tracing in thyroid cancer and sentinel lymph node biopsy in breast cancer. This single-center, single-blind, dose-escalation phase I clinical trial aimed to investigate the safety of MHI on lymph node tracing in gastric cancer. In this study, four dose groups (1.0 mL, 1.5 mL, 2.0 mL, and 3.0 mL) with 3 gastric cancer patients in each group were set. The safety, tolerability, pharmacokinetics and preliminary efficacy of different doses were investigated. Results showed that none of the patients experienced dose-limiting toxicity or developed serious adverse events or adverse drug reactions. Pharmacokinetic analyses revealed minimal absorption of the tracer, resulting in low and transient blood drug concentrations across all participants. The mean time to peak concentration was (0.561 +/- 0.3728) h (with mean peak concentration (C-max) of 10.300 ng/mL), (0.500 +/- 0.0167) h (mean C-max of 13.687 ng/mL), (0.494 +/- 0.0096) h (mean C-max of 30.933 ng/ mL), and (0.661 +/- 0.2791) h (mean C-max of 21.067 ng/mL) in the 1.0 mL, 1.5 mL, 2.0 mL, and 3.0 mL dose groups, respectively. The mean lymph node staining rates were 21.0%, 24.7%, 32.5%, and 44.5%, and the mean metastatic lymph node staining rates were 20.6%, 36.1%, 42.4%, and 21.0% in each group. This study confirmed that MHI was safe, well-tolerated, and had low systemic effects when used for lymphatic tracing of gastric cancer, and the tracing effect was better in the 3 mL dose group. This trail was registered on the website of Centre for Drug Evaluation State Drug and Food Administration (http://www.chinadrugtrials.org.cn/index.html) with the name of clinical study of lymphatic tracer in lymph node tracing of gastric cancer, the code was CTR20201906.