Abstract: To better analyze the seismic site effects in land reclamation areas and provide a scientific basis for earthquake-resistant engineering design, this study investigates the Dongjiang port land reclamation area in Tianjin. Integrated short-period flow seismometers were used to collect ground motion noise at the site, and the consistency of horizontal-to-vertical (H/V) spectral ratio peaks was analyzed using noise level and H/V ratio methods. Based on long-term observations at 26 fixed points, ground motion noise was recorded, and a normalized profile map was generated by converting the H/V curve data using a formula based on dominant frequency and depth. The analysis revealed unstable H/V peak values in the low-frequency range below depths of 50～200 m, suggesting that weak wave impedance interfaces caused by backfill soil exist in the shallow subsurface, with relatively distinct soft sediment interfaces near depths of 50～200 m. The dominant frequencies at the site range from 0.6 Hz to 1.6 Hz, with amplification factors between 1.96 and 3.99. This study provides a useful reference for estimating site effects in the Dongjiang port land reclamation area.