Well-defined KZnF3:Yb3+, Er3+, Mn2+ nanocubes were successfully prepared by a facile solvothermal method. The XRDand SEM measurements results show that the cubes have good crystallinity and the average cubic size is about 40nm The incorporation of Mn2+ ions into KZnF3:Yb3+, Er3+ leads to the great increase in the red to green luminescence intensity ratios from 10:1 to 214:1 and the red emission was enhanced about 20 times. The selective enhancement of red upconversion luminescence of Er3+ can be ascribed to the exchange energy transfer interactions between Er3+ ions and Yb3+-Mn2+ dimers. The case of KZnF3:Yb3+, Er3+, Mn2+ provides a new strategy to get the pure red upconversion luminescence, which show potential applications in the fields of lighting, displays and biological nano labels.