One of the main purpose in cosmology is to determine an equation of the state (EoS) of dark energy (DE). DE dominates the evolution of our universe. Since DE is currently in dominant phase, it accelerates our universe. Usually the feature of DE is classified as canonical or non-canonical field by the value of EoS if it is more than -1. To understand the behavior of DE, type Ia supernovae (SNe Ia) are often used. In addition to this, gamma-ray bursts (GRBs) are also studied to disclose its properties because it can be found at high redshift region. These studies indcates that GRBs can be the candidate of the cosmological proves. For instance, Yonetoku relation and Amati relation are established. These relation can be used to constrain the cosmological models. In this work, we apply an EoS which varies over time and reveal the density evolution of DE. Then, we use Markov chain Monte Calro method to constrain the EoS from the SNe Ia and GRBs. We find that DE prefers that there is a crossing of the phantom barrier near our time.