A group signature scheme and a threshold group signature scheme based on Bilinear Paring are proposed, there are multiple security strategies in these two schemes. These schemes have forward security which minimizes the damage caused by the exposure of any group member's signing key, and does not affect the past signatures generated by this member; meanwhile, ahead signature generated by a group member before the joining date can be prevented via this strategy. Moreover, this scheme support the group member revocable function efficiently and further has no requirement for time period limits.