To proble into effects of phosphogypsum on growth and nutrient balance of broomcorn and soil available nutrient in strongly acidic soil,pot cultivated trials were conducted to investigate why phosphogypsum was better than lime in amelioring acidic yellow soil.Results showed that even if sufficient nutrient was supplied broomcorn grown in strongly acid yellow soi1 were severly affected by A1 toxicity broomcorn seedlings had not grown well after germination without application of phosphogypsum or lime.However,plant growth was improved by application of phosphogypsum(x1) or lime(x2)which could increase soil pH decrease the concentration of exchangable A1 in strongly acidic soil.The regresstion equations were below: y=6.88 11.92x-1.65x2,R=0.983;y=6.88 6.39x-0.72x2,R=0.996.Lime was superior to phosphogypsumin alleviating A1 toxicity and raising contents of calcium,and was inferior to phosphogypsum in increasing available nitrogen,phosphorus,potassium in broomcorn plant.The content of phosphorus in plant by application of phosphogypsum was more 117.0%~200.0% than that by application of lime.Compared to application of lime,application of phosphogypsum could increase contents of nitrogen,phosphorus,potassium and calcium,and sustain moderate N/P,N/K and K/P and improve balance of nitrogen,phosphorus,potassium and calcium in broomcorn plant.Moreover,phosphogypsum was also superior to lime in increasing available nitrogen,phosphorus,potassium,calcium in strongly acidic soil.