Hemocyanin is an extracellular copper-containing protein present in the hemolymph of both mollusks and arthropods. Several studies have shown that hemocyanin could produce some fragments with antibacterial and antifungal activities. Interestingly, we recently found 12 chemically synthesized peptides, predicted by bioinformatics, derived from hemocyanin in the shrimp Vibrio parahaemolyticus and However, to date little is known about antifungal activities of these peptides. Here, by using the methods of chemical synthesis, antifungal experimentation, and microscopy, we attempted to determine the anti- activity of the 12 chemically synthesized peptides and the possible mechanism. Our results showed that six synthetic peptides (B2, B10, B13, B14, S7, and S9) exhibited obvious anti- activity at a concentration of 80 μg/mL, with the inhibition rate ranging from 30% to 100%. We selected B10 for further analysis, including the effect of concentration and shape of spores. Light microscopy and scanning electron microscopy analyses showed that the sporangium of grew more slowly under the action of B10 and the experimental groups treated for 30 h, 35 h, and 40 h had significantly reduced spore numbers (50%-90%); additionally, the sporangial morphology of the experimental groups was significantly smaller than that of the control group. Thus, it was preliminarily shown that six of the 12 chemically synthesized peptides from activities by inhibiting sporangium growth. This research is of significant value in explaining the immunological activity and functional mechanism of the fragments of shrimp hemocyanin.