[en] Semiconductor photocathode and metal photocathode have different properties. To consider the properties of both, we studied a new type of photocathode - ion implanted photocathode. Cesium ions are implanted into a metal substrate. A photocathode preparation chamber is set up to make this photocathode. A cesium ion source is attached to the common photocathode preparation chamber. In the past two years, we finished making this photocathode and did research on its properties. A series of experiments have been done with different metal substrates, implanting dosages and implanting energies, in order to get a kind of photocathode material with high quantum efficiency and good stability. An increase of quantum efficiency after implantation has been observed. A more interesting result is that the emission spectrum becomes broader