From September 2014 to June 2015, eight field tracer experiments were conducted in a 90-m-length stream reach of an agricultural headwater stream, which is dominant of reeds and belongs to the Ershibu River watershed in Hefei city, using a constant-rate injection of NaCl. Based on the data sets of tracer experiments, the relative deviation of the peak values (HI) of the chloride ion concentrations was calculated with the OTIS model at the condition of ignoring the impact of transient storage or not, and the efficiency for transient storage was interpreted by using multiple transient storage metrics. The results showed that all the values of transient storage exchange coefficient (α) were in the order of magnitude of 10^-4 in different seasons. The values of HI ranged from 2.60% to 12.54% without considering the interaction between the main channel and transient storage zone, with the mean value of 5.35%. There was a significant logarithm function relationship between HI and discharge (Q), which was decreased gradually with the increase of the value of Q. Moreover, HI had obvious linear relationship with the ratio of cross-sectional area of storage zones to main channel cross-sectional area (A_s/A), and which was gradually increased with the increase of the A_s/A. Significant differences were exhibited between the main channel residence time (T_c) and the transient storage residence time (T_s) in all eight tracer experiments, and the transient storage capacity in the spring and early summer was stronger than that in the autumn and winter. The values of A_s/A and F_med²⁰⁰ were respectively in the range of 1.036 to 1.627 and 8.10% to 23.03%. This suggested that the stream with a dominant plant of reeds has a higher capacity for transient storage.