Anthracnose caused by Colletotrichum nymphaeae and gray mold caused by Botrytis cinerea are the most epidemic fungal diseases causing significantly losses in strawberry plantings. The objective of the study is to determine the antifungal activity of neem (Azadirachta indica A. Juss.) seed extracts and preparing new formulated antifungal agent. Plant extracts including alcoholic, aqueous and oil were extracted from neem seeds and used in concentrations of 1000, 2000, 4000, 8000 and 10,000 µl/l to control the vegetative mycelial growth of pathogens. The results showed that alcoholic extract had highest antifungal effect and used for the formulation. The concentration of 10,000 microliters of alcoholic extract showed 91.6 % inhibition of gray mold disease, while it inhibited 80.66 % in anthracnose disease and a significant difference was observed between them. For encapsulation of alcoholic neem extract with plant biopolymers with new changes, the separation method of water-miscible solvent through precipitation with salt was used. The results showed that the best effect of the formulation was observed at a dose of four per thousand. Inhibition at this concentration as the best option in terms of controlling gray mold and anthracnose disease was 86.3 % and 79.38 %, respectively, and they were placed in the same statistical group (d). This formulation is designed to determine the minimum concentration threshold and reduce the consumption of alcoholic extract. Based on the results, the use of formulated alcoholic extract of neem seed as an alternative to chemical fungicides can help control anthracnose and gray mold in strawberries.