Abstract: The study aims to investigate the pharmacokinetics (PK) and preliminary safety of desaminotyrosine (DAT) in Sprague-Dawley (SD) rats and establish an ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determining DAT content in blood and tissues, obtaining pharmacokinetic parameters and tissue distribution characteristics of DAT in rats after intragastric administration of three single doses and multiple doses. Evaluate the safety after 7 days of administration, including general condition, toxic reactions and mortality, organ-to-body weight ratios, hematological parameters, blood biochemistry and electrolyte levels, as well as observe pathological changes in organs. The results indicated that the detection methods conformed to the requirements for biological sample analysis. The absorption and elimination of DAT in rats occurred rapidly, with PK parameters such as C_max and AUC_0-t values increasing in accordance with the dose ratio. No significant differences were observed between single and multiple administrations. DAT was primarily distributed in the kidneys > liver > testes > lungs > heart > spleen, with minimal penetration through the blood-brain barrier. Administration for 7 days at doses ≥100 mg·kg^-1·d^-1 induced gastrointestinal irritation, body weight loss, and liver/kidney injury. The UPLC-MS/MS analysis in the study was sensitive, accurate, and rapid. The PK parameters aligned with a linear PK profile at single doses ranging from 25 to 125 mg·kg^-1, with no accumulation observed after multiple doses. DAT demonstrated good safety at the dose of 50 mg·kg^-1·d^-1, which will provide a basis for further development of its pharmaceutical value. This experiment was approved by the Laboratory Animal Ethics Committee of Guangdong Provincial Hospital of Traditional Chinese Medicine (Grant No: 2021042).