A pot experiment was  carried out at the Experimental  Farm and Laboratory of Horticulture Department,  Faculty  of Agriculture , Benha University , Egypt , uring 2019 and 2020 successive growing seasons.  The study was carried out to define the efficiency of various biofertilizers; Minia Azotein, Frankia and Visicular Arbuscular Mycorrhiza, each alone or combined with two doses of chemical fertilizer NPK  at 75% and 50% from the recommended dose (350:200:100 kg/ fed) and/or the full dose of 100% NPK to improving some chemical characteristics of Casuarina equistifolia seedlings grown in sandy soil and improving its macronutrient's content N, P and K. Results showed that all treated seedlings of casuarina with Frankia 50g/ plant, and Visicular Arbuscular Mycorrhiza 50 ml/plant in combination with 75% NPK T8 and T10 and or NPK 100% recommended dose (10:5:2.5g/plant) recorded significant increases in total chlorophylls a,b, carotenoids, N, P , K and carbohydrate percentage compared to the other treatments and control. The highest macronutrient content N, P and K values were found with the abovementioned treatments followed by Minia Azotein  combined with 75%NPK  in both seasons while the other treatments did not attain any significant variens in soil's macronutrient content N, P and K and chemical characteristics parameters. It can be concluded that Frankia 50g/plant , Visicular Arbuscular Mycorrhiza 50 ml/plant with 75% of recommended dose (7.5:3:75:1.875g/plant) and/ or 100% of recommended dose of  NPK (10:5:2.5g/plant) were the best in improving soil's macronutrient and chemical  characteristics of Casuarina equistifolia  seedlings.