Abstract: Field experiments on soybean variety Hampton-266A were carried out for three years at Sindh Agriculture University, Tandojam on silt loam soil. Factorial experiments in Randomized Complete Block with four replications were carried out with three soil moisture stress levels (3, 5 and 8 bar tension) and two fertility levels (NPK 50-60-30 and 50-90-30 kg ha-1). The data demonstrated that seed yield was highly significantly affected by moisture stress and fertility levels. The seed yield reduced by 28 and 20% at 8 and 15 bars respectively as compared to 3 bar soil moisture stress. The seed yield was about 10% more in 90 kg P2O5 Per hectare as compared to 60 kg P2O5 per hectare. It is therefore suggested that soybean crop should be irrigated when soil moisture reaches at the level of 3 bar, where satisfactory yield could be obtained.