Magnesium and phosphorus are critical macronutrients for plant growth.At present，magnesium deficiency and low phosphorus use efficiency are becoming the key limited factors for nutrient management in green crop production in China.The nutrient supply of magnesium and phosphorus in soil barely meets the demand of crops which can result in low crop yield and poor quality，especially in acidic soils in the south of China.There are complex interactions between magnesium and phosphorus nutrients.For fertilizers，it affects the phytoavailability of magnesium and phosphorus. For soil，it works on the nutrient fixation and release of magnesium and phosphorus.For crops，it does not only promote the absorption and utilization of magnesium and phosphorus nutrients effectively，but also improves crop yield and quality.As mentioned above，there are various types of interactions between magnesium and phosphorus nutrients in the fertilizer-soil-crop system which requires recognizing and understanding the processes and mechanisms of Mg-P interactions systematically，thus can provide scientific basis for innovative design of green and high efficiency fertilizers and efficient nutrient management practices.