Gladiolus is commercially propagated by its underground structure for production of flowers and corms as well as cormels. A field experiment was conducted during two successive seasons of 2018/2019 and 2019/2020 to investigate the effects of compost as an organic fertilizer (0, 5, 10 and 15 ton/fed) and Microbein biofertilizer (M.B.) at 50 ml/plant and/or some antioxidant treatments (salicylic and ascorbic acids) on corm and cormels production and chemical constituents of Gladiolus grandiflorus var. Jester plants. The obtained results indicated that corm diameter (cm), number of new cormels/plant, dry weight of corm and cormels (g), as well as, chemical constituents including chlorophyll a, b, carotenoids in the fresh leaves and percentages of N, P and K in the dry leaves were gradually increased by increasing levels of compost with significant differences. The highest corm diameter (5.27 cm) was produced by plants received compost at 15 ton/fed in combination with Microbein biofertilizer (M.B.) plus salicylic acid plus vitamin C while least size (2.5 cm) of corm was observed in control plants. All six treatments of Microbein biofertilizer (M.B.) at 50 ml/plant and/or some antioxidant (salicylic and ascorbic acids) treatments each at 50 ppm significantly increased corms and cormels production and the content of chemical constituents in comparison with control treatments. Treatments of Microbein biofertilizer (M.B.) plus salicylic acid plus ascorbic acid (vit. C) was more effective than other treatments for corm and cormels production, as well as, photosynthetic pigments content (mg/g. F.W.) and the percentage of nitrogen, phosphorus and potassium, in most cases. The interaction between compost, Microbein biofertilizer (M.B.) and/or some antioxidant (salicylic and ascorbic acids) treatments were significant for all previous characters. In some cases, the highest values of corms and cormels production were achieved by compost (15 ton/fed) in combination with Microbein biofertilizer (M.B.) plus salicylic acid plus ascorbic acid (vit. C) followed by 15 ton/fed compost with M.B. + vit. C then 10 ton/fed compost with M.B. + salicylic acid + vit. C which recorded the highest contents of pigments and elements of N, P and K.