Polar codes have drawn lots of attentions for the capacity-achieving property and low encoding/decoding complexity. As two promising decoding algorithms, successive cancellation (SC) decoding shows better performance but limited by high latency. Otherwise, belief Propagation (BP) algorithm presents high throughput yet with performance degradation. In this paper, a hybrid decoding architecture combining SC and BP decoding is proposed, which could process both algorithms in unified module within one decoding step. The simulation result reflects a tradeoff between decoding latency and performance with different decomposition levels. In terms of hardware implementation, the adjustable architecture is implemented based on systolic BP decoder and look-ahead SC decoder. The hybrid decoder offers the flexibility and generality which could apply on different conditions.