To reveal the dynamic characteristics of interspecific relationships among woody plants in Shanghai urban parks during different construction periods, this study 14 urban parks belonging to 4 periods (before 1995, 1995-2004, 2005-2015, and after 2016). 1,434 plant community quadrats (1m 10m) were surveyed, focusing on 29 arbor species and 27 shrub species with an important value ≥ 5. Interspecific associations were analyzed using the variance ratio (VR), χ2 test, Pearson correlation coefficient, and Spearman rank correlation coefficient. The results showed that the overall associations of arbors and shrubs in each period were significantly positive (VR > 1, p < 0.05), and their stability gradually increased with the passage of construction time, with the VR value rising from 1.43 in Period I to 1.98 in Period IV. There were obvious differences in interspecific relationships in the arbor layer: in the early stage, non-significant negative associations dominated, such as between Camphora officinarum and Taxodium mucronatum; in the later stage, significant positive associations formed, such as between Triadica sebifera and T. mucronatum. The shrub layer maintained a strong positive association throughout all periods, with the VR reaching 1.98 in Period IV. Among them, the proportion of positively correlated species pairs shown by the Spearman rank test reached 23.81%, significantly higher than the 4.76% shown by the Pearson test, indicating that the Spearman rank test is more sensitive to capturing weak synergistic relationships. Therefore, it is suggested that differentiated plant configuration strategies should be adopted for parks in different construction periods. For the renovation of early-stage parks, priority should be given to replacing arbor species with negative associations; in all periods, clustered configuration of adaptable shrub species should be strengthened to improve the stability of plant communities.