Copyright © 2012 Chenwei Wang and Ercai Chen. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Let be a weakly conformal iterated function system on with attractor . Let be the canonical projection. In this paper we define a new concept called “projection pressure” for and show the variational principle about the projection pressure under AWSC. Furthermore, we check that the zero of “projection pressure” still satisfies Bowen's equation. Using the root of Bowen's equation, we can get the Hausdorff dimension of the attractor .