Phosphorus is one of the three nutrients generally added to soils. However, the amount of available P in alkaline and calcareous soils is limited to be sufficient for normal plant growth. Therefore, the first part of this study was devoted to evaluate the effect of different application rates of sulphur (0.0; 0.5;1.0;2.0 and 3.0 Tons/acre) at various inoculated periods (1; 2; 3 and 4 weeks) with or without sulphur-oxidizing bacteria on the availability of P for sandy; clay loam; and calcareous soils. The second part, was designed as field experiments for garlic to compare the effect of different rates of P ( 0, 100; 200; 300 Kg. of Super Phosphate /acre)with and without different rates of elemental sulphur (0.0; 0.5; 1.0 and 2.0 Tons/acre) on garlic yield and bulb weight. The availability of P increased with increasing both sulphur application rates and inoculated period of soils with sulphur-oxidizing bacteria. The magnitude of increasing phosphorus availability was dependent upon soil type at the following order: calcareous soil > sandy soil > clay loam soil. It was concluded that application of one or two tons sulphur per acre (depending upon soil type ) resulted in supplying a suitable amounts of available phosphorus. Available phosphorus increased from 2.2 to 51; 0.9 to 25 and 9.5 to 19 ppm for calcareous; sandy and clay loam soil, respectively. The results of field experiments indicated the drop in soil pH as a function of applied sulphur which, influenced the availability of phosphorus. The yield of garlic increased from 4 to 5.2 Tons/acre by increasing application rate of P from 0 to 400 Kg. per acre Super Phosphates alone. Also garlic yield increased from 4 to 5.7 Tons by application of 2 Tons acre of sulphur alone per. This means that application of sulphur alone has contributed to convert the phosphorus present in soil from insoluble to soluble forms for garlic plant and to be more productive than that treated with 400Kg per acre super phosphate alone. However, the combination between the application of high rate of P and S resulted in increasing the garlic yield from 4 to 7.1 Tons/acre. Key Words: Sulphur, Phosphorus, Garlic, Fertilizers, and inoculation with sulphur-oxidizing bacteria.