Optimized　in　lightweight,　compactness　and　high　temperature　sustaining　the　shielding　materials　for　neutron　and　gamma　radiation　were　designed　based　on　genetic　algorithms.　Three　kinds　of　materials　studied　by　this　method　were　designed　and　simulated　with　MCNP　code,　and　results　were　compared　with　those　from　iron　etc.　The　total　shielding　effects　of　the　materials　with　certain　thickness　for　fission　neutron　and　γ-ray　are　all　much　better　than　iron,　and　the　equivalent　masses　are　lower　than　iron　at　same　shielding　effect.