In this paper, we observe for the first time that a metastable beta-Zr in the body-centered cubic (BCC) structure can form via a new phase transformation route. The as-received alpha-Zr in the hexagonal closed-packed (HCP) structure transforms partially to the gamma-Zr in the face-centered cubic (FCC) structure via Shockley partial dislocations during deformation, while the gamma-Zr can continuously transform to the beta-Zr by a uniform shear along the < 112 >(FCC) direction on the < 111 >(FCC) plane during subsequent hot deformation. The beta phase is in a Pitsch-Schrader relationship ((110)(BCC) parallel to(0001)(HCP), [1 (1) over bar0](BCC)parallel to[10 (1) over bar0](HCP)) with the matrix alpha phase and in a Nishiyama-Wassermann relationship ((110)(BCC)parallel to(1 (11) over bar)(FCC), [1 (1) over bar0](BCC)parallel to[12 (1) over bar](FCC)), with the gamma phase, both of which have not been reported in Zr previously. Combined with corresponding molecular dynamics simulations, the phase transition mechanism and stability of the beta phase are studied. The results show that the beta-Zr phase can be retained in the gamma phase when the cooling is fast enough.