An electron cyclotron resonance heating system will be constructed in the near future for ECH and ECCD investigation on HL-2A tokamak. The new ECRH system will provide HL-2A with a power capability of 1 MW for 1 s at frequency of 70 GHz. Consequently, it is very important to choose a suitable gyrotron and some components for HL-2A ECRH system.