An abdominal exercising device includes a base supporting member having a seat element for supporting a user, two handles each having a lower portion rotatably attached to the base supporting member with a pivot shaft, two spring biasing members engaged between the handles and the base supporting member for biasing the handles relative to the base supporting member, and two adjusting members are engaged with the beams of the base supporting member respectively and engageable with the spring biasing members for adjusting the spring biasing members relative to the base supporting member and the handles and for adjusting the spring biasing force to the handles and for users of different strengths.