A method for manufacturing a quantum dot and a quantum dot are provided. The method includes adding a core semiconductor precursor solution into a seed composition solution. The seed composition solution includes a seed composition, and the seed composition is a dendrimer-metal nanoparticle composite. The core semiconductor precursor solution includes a first semiconductor ion and a second semiconductor ion. The method also includes carrying out a first synthesis reaction to form a core semiconductor material wrapping the seed composition. The core semiconductor material is formed by combining the first semiconductor ion with the second semiconductor ion.