This investigation was carried out throughout the two successive seasons of 2021 /2022 and 2022 /2023 at the Sids Horticultural Research Station, ARC, Egypt, to explore the response of Nigella sativum L. plants to some microbial inoculants, humic acid and phosphorous on productivity and quality characteristics. Treatments were inoculated seeds with (Bacillus megatherium and Mycorrhizae) and addition of H.A. plus three rate (50, 100 and 200 kg) of calcium super phosphate. It was observed that the plant growth, root length, seed yield, volatile and fixed oil % and yield as well as chemical constituents were improved by treated plants with microbial inoculants and humic acid plus phosphate. The highest values of the growth characters, seed yield and volatile and fixed oil of Nigella sativum L. resulted from inoculated seeds with microbial inoculants, humic acid at 4 kg/fed. and andaddition 100 kg calcium super phosphate.