A study was carried out during two successive seasons, of 2002:9003 and 2003 {2004 at EL-Sheikh Zoweid, North Sinai Governorate .The cultivar Spunta produced locally and obtained from the union of producers and exporters of horticultural crops was used . The aim of the study was to investigate the effect of different levels of compost and biofertilizers on potato growth, the chemical constituents and productivity of potato grown in sandy soil using drip irrigation. The results were as follows : 1-Using compost and biofertilizer 15 tons ffeddan +2 or 4 liters of rizobecterien enhanced vegetative growth ( plant height ,leaves fresh weight , leaves dry weight ,stem fresh weight and stem dry weight ) The lowest vegetative growth was noticed due to the application of 20 tons ffed. + 4 liters of rizobecterein. 2- The application of compost 15 tons I led. +4 liters of rizobecterein gave the highest total yield ( 29.8 tons fled. ) compared with either chicken manure + bio fertilizers (17.9 tonsifed.) or compost at 20 tons r ted. [ 15.9 tons I fed). 3- The highest marketable yield was obtained by applying 15 tons compost l feddan + 4 liters of rizobecterein (35%). The lowest marketable yield was produced at using 20 tons I feddan of compost + 2 liters of rizobecterein (612%).