The present invention relates to the area of nanoparticle engineering. More particularly, the present invention relates to a positively-charged polyamine carbon dot and use thereof. The present invention also relates to a method for preparing a positively-charged polyamine carbon dot and a composition.本發明是關於一種碳化多胺粒子領域,特別是關於一種帶正電荷碳化多胺粒子,及其應用於抗菌之用途。本發明還有關於製備帶正電荷碳化多胺粒子及組合物的方法。