Abstract: Nitrogen and phosphorus retention for a typical drainage ditch in Guanzhenhe Branch, a first-order stream dominated by domestic sewage in the rural-urban continuum of Hefei, was characterized. Field tracer experiments were carried out for five replications by addition of a conservative tracer (NaCl) and nutrients (NH₄Cl and KH₂PO₄) along the study reach. Based on the experimental data, hydrological parameters (e.g., dispersion coefficient D, stream channel cross-sectional area A, storage zone cross-sectional area A_s, and stream storage zone exchange coefficient α) and the first-order nutrient decay coefficients (e.g., decay coefficient in main channel λ and decay coefficient in storage zone λ_s), were estimated with the transient storage OTIS (one-dimensional transport with inflow and storage) model. Nutrient spiraling metrics (i.e., uptake length S_w , mass transfer coefficient V_f, and nutrient uptake rate U) were subsequently calculated based on the nutrient spiraling theory. Regression and correlation analysis were further conducted with SPSS statistical software. The results showed that:1) The average value of As/A was 0.35, and was significantly negatively correlated with discharge (Q). 2) The order of magnitude of α was 10^-3, while the mean value of α was 2.49×10^-3 s^-1. S_w -NH₄ and S_w -PO₄ (S_w of NH₄-N and PO₄-P) reached their maximum values of 934,0 and 47,8 m, respectively, indicating that Guanzhenhe Branch was not capable of retaining nutrients efficiently. Meanwhile, the negative values of S_w -NH₄ and S_w -PO₄ suggested that the study reach even acted as a nutrient source. 3) Correlation analysis results showed that V_f-NH₄ was negatively correlated with water depth and Q, respectively. In addition, both V_f-NH₄ and U_f-PO₄ increased with stream width. 4) Nutrient spiraling metrics were not statistically related to ambient concentrations of NH₄-N and PO₄-P in regression analysis. In general, high nutrient concentrations restricted the effect of nutrient retention in Guanzhenhe Branch. Excessive nutrient sources coming from domestic sewage should be reduced to improve the stream retention capacity.