Abstract: The effects of phosphate fertilizer application rates on the yield of sweet potato variety Longshu 601 (a cultivar with early maturity and high yield) were studied, in order to provide technical support for the realization of combining good methods with improved varieties and promoting the demonstration and promotion of new varieties. In this experiment, the single-factor randomized block design was used to analyze the effects of different phosphate fertilizer application rates (0, 37.5, 75, 112.5, 150, and 300 kg·hm^-2) on the agronomic traits, yield and yield components of sweet potato with no fertilization treatment as the blank control (CK). The results showed that compared with no fertilization, the commercial potato rate of sweet potato with the fertilization treatments was all significantly increased. There was a significant difference between the application of phosphate fertilizer (except 112.5 kg·hm^-2) and no application of phosphate fertilizer, and the potato yield treated with the application rate of 75.0 kg·hm^-2 and 150.0 kg·hm^-2 were higher. The yield treated with different fertilizer application rates was significantly higher than that treated with no fertilization (CK). Compared with no phosphate fertilization treatment (P2), the yield of Longshu 601 treated with the appropriate phosphate fertilization was significantly increased, and the maximum yield was 61.06 t·hm^-2 when treated with the phosphate application rate of 112.5 kg·hm^-2(P5). The quadratic curve function fitting was carried out between the phosphate fertilizer application amount and the yield of fresh potato of Longshu 601. The fitted equation was Y=-0.000 34X²+0.114 014X+49.313 8, r=0.965 5. According to the simulated calculation of the peak of quadratic curve, the yield of fresh potato of Longshu 601 reached the highest (58.87 t·hm^-2) when the application amount of phosphate fertilizer was 167.67 kg·hm^-2. The economic benefit of sweet potato could be improved by applying the proper amount of phosphate fertilizer, and the highest investment rate could be reached when treated with the phosphate fertilizer application rate of 112.5 kg·hm^-2 (P5). In other words, the investment rate of fertilizer was the highest (reaching 12.55) when applying the nitrogen fertilizer (N) of 90 kg·hm^-2, potassium fertilizer (K₂O) of 150 kg·hm^-2 and phosphate fertilizer (P₂O₅) of 112.5 kg·hm^-2.