This study was conducted to evaluate the impact of bio fertilizers namely, Azotobacterine (Azotobacter chroococcum) and phosphorein (Bacillus polymyxa) and mineral N, P and K fertilizers at the rates of 25, 50 and 100% for each fertilizer (from the doses recommended by Ministry of Agriculture) as well as ascorbic acid at the rate of 400 ppm on growth (plant height, number of branches and herb fresh and dry weights/plant), yield (dry weight of sepales/plant and feddan and weight of seeds/plant and feddan) of roselle plants (Hibiscus sabdariffa, L.) under different soils (clay soil at Dar El-Ramad farm, sandy loam and saline loamy sand soil at Demo farm, Faculty of Agriculture) at El-Fayoum governorate conditions. The data obtained showed that, bio and mineral (NPK) fertilizers increased the above characters of roselle plants under different soils of experiment. The maximum increase of these characters was obtained by the treatment clay soil × 100% NPK + biofertilizers × 400 ppm ascorbic acid, followed by clay soil × 50% NPK + biofertilizers × 400 ppm ascorbic acid as compared to saline loamy sand soil × non fertilizer × zero ascorbic acid treatment, although, the differences between these treatments and mineral fertilizer at the rate of 100% NPK alone were insignificantly. Therefore, it is economically and environmentally recommended to inoculate roselle seeds with mixture of Azotobacter + Bacillus and fertilize these inoculated plants with 50% plus 400 ppm ascorbic acid improve the vegetative growth and augment the yield components of roselle plants under clay soil with spraying 400 ppm of ascorbic acid were obtained the best results of this work study.