Abstract:  A field trial with Haijiao No.4 (a Capsicum annuum cv.) was conducted in Chengman County, Hainan, China to investigate effects of balanced fertilizer application with N, P, K and Mg on its yield, fruit quality, plant nutrient content and nutrient uptake. It is found that the fruit yield was significantly influenced by N, K and Mg fertilizers. Application of P had no effect on fruit production. Yields decreased by 38.2 %, 36.6% and 21.8 % in the treatments of PKMg, NPMg and NPK, respectively. K fertilizer significantly increased the vitamin C content in the fruits. Balanced fertilizer application increased nutrient content in leaves and stalks and improved nutrient uptake by plant. The use efficiencies of N, P2O5, K2O and MgO under the balanced fertilizer application were 22.9 %、2.4 %、33.4 % and 4.0 %, respectively. When 1000 kg fruits were produced, the absorbed N, P2O5, K2O and MgO were 3.69, 0.53, 4.15 and 0.38 kg, respectively. The absorption ratio of N, P, K and Mg was 1:0.14:1.12:0.10.