Soil column leaching experiment and soil pot experiment were conducted in this study in order to clarify the effects of nano carbon sols (NCS) on pH, EC and nutrient contents of alkaline soil. The results showed that NCS obviously reduced soil pH and EC values, the maximal reduced value were 0.49 units for pH and 0.14 mS/cm for EC, respectively, and the reducing effect was more obvious under higher NCS concentration. NCS significantly increased nitrate contents in 0-80 cm soil, averagely increased by 21.99%, 27.34% and 25.57% under different treatments, respectively, but it influenced little on ammonium nitrogen content. NCS increased available phosphorus contents in different soil layers, averagely increased by 10.10%, 13.72% and 12.30% respectively under different treatments, but the effects were different in different soil layers. NCS had higher activation effect on soil potassium, could increase soil available potassiecm contents significantly, averagely increased by 6.62%, 12.54% and 13.18% under different treatments. Therefore, NCS can obviously reduce pH and EC value, improve the available nutrient contents in alkaline soil and thus is effective in improving alkaline soil.