Polymer-network stabilized blue phase liquid crystal (BPLC) has been studied for decade; however, mechanism of hysteresis is not fully understood. In this report, based on the interaction between polymer-network and blue phase liquid crystal, mechanism of hysteresis was proposed. Results and discussion were confirmed by experimental data and literature reports. Mechanism of hysteresis is governed by three dominated factors, primary factor is relaxation ability of BPLC, secondary is steric hindrance of polymer network and tertiary is anchoring force between BPLC and polymer network. Although experimental results showed trade off in eliminate hysteresis, an effective approach of dual frequency effect was applied and hysteresis was significantly reduced from 4.44% to 0.01%. (c) 2013 Elsevier Ltd. All rights reserved.