Abstract: Per- and polyfluoroalkyl substances (PFASs) have drawn significant global concern due to their environmental persistence, bioaccumulation potential, and the associated ecological and health risks. Agricultural environment acts as critical sink and secondary source of these pollutants. To support the accurate assessment of farmland safety, this study established a robust analytical method for the simultaneous determination of five ultrashort-chain PFASs in paddy water and soil. Water samples were pretreated using both direct injection and solid-phase extraction (SPE), while soil samples were extracted with methanol followed by SPE cleanup. All extracts were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) under multiple reaction monitoring (MRM) mode, with quantification performed via the internal standard method. The results demonstrate good linearity for the five target compounds over specified concentration ranges (TFA: 50-2 000 ng·L^-1; other four ultrashort-chain PFASs: 10-2 000 ng·L^-1), with correlation coefficients (R²) ≥ 0.998. For water samples processed by direct injection, recoveries ranged from 90.3% to 105% at spiked levels of 60-200 ng·L^-1, with relative standard deviations (RSD, n=6) of 0.9%-3.6%. For the SPE method, recoveries were between 75.6% and 95.3% at spiking levels of 0.5-5 ng·L^-1, with RSD of 1.0%-5.1%. In soil, recoveries ranged from 74.2% to 91.2% at spiked concentrations of 20-200 ng·kg^-1, accompanied by RSD of 1.2%-3.0%. The method detection limits for the five analytes were between 0.056 and 11 ng·L^-1, with quantification limits of 0.5-60 ng·L^-1 in water and 20 ng·kg^-1 in soil. This method is simple, sensitive, and reproducible, making it well-suited for the rapid screening and accurate quantification of ultrashort-chain PFASs in complex farmland matrices.