To study the effects of superphosphate (SP) on the NH₃ and greenhouse gas emissions, vegetable waste composting was performed for 27 days using 6 different treatments. In addition to the controls, five vegetable waste mixtures (0.77 m³ each) were treated with different amounts of the SP additive, namely, 5%, 10%, 15%, 20% and 25%. The ammonia volatilization loss and greenhouse gas emissions were measured during composting. Results indicated that the SP additive significantly decreased the ammonia volatilization and greenhouse gas emissions during vegetable waste composting. The additive reduced the total NH₃ emission by 4.0% to 16.7%. The total greenhouse gas emissions (CO₂-eq) of all treatments with SP additives were decreased by 10.2% to 20.8%, as compared with the controls. The NH₃ emission during vegetable waste composting had the highest contribution to the greenhouse effect caused by the four different gases. The amount of NH₃ (CO₂-eq) from each treatment ranged from 59.90 kg·t^-1 to 81.58 kg·t^-1; NH₃ (CO₂-eq) accounted for 69% to 77% of the total emissions from the four gases. Therefore, SP is a costeffective phosphorusbased fertilizer that can be used as an additive during vegetable waste composting to reduce the NH₃ and greenhouse gas emissions as well as to improve the value of compost as a fertilizer.