Wnt/β-catenin signaling plays an important role in regeneration in multiple species such as planaria. The study aimed to investigate the effect of Wnt/β-catenin signaling on the regeneration in the annelid, Capitella teleta. Sustained incubation of samples after amputation in 30 μmol/L XAV-939, an exogenous Wnt/β-catenin signaling small molecular inhibitor, revealed that the regeneration of C. teleta was inhibited, with significantly slower regeneration compared to that in the control group and failure to form a regeneration blastema. Neural and muscle growth during regeneration were also affected by inhibition of Wnt signaling revealed by neural and muscle labeling. Subsequently, EdU labeling indicated that the number of proliferating cells in the XAV 939-treated group was significantly less than that in the control group, suggesting that the suppression of the Wnt/β-catenin signaling may have affected the proliferating cells during the regeneration of C. teleta, which alsofurther demonstrating that the Wnt/β-catenin signaling may be involved in the regeneration of C. teleta, and play an important role in the early stage of regeneration. Comparative studies on the regulation of regeneration by wnt signaling in several typical species have shown that the Wnt signaling is relatively conserved in the whole-body regeneration of Cnidaria and Lophotrochozoa.