Recently, broadband THz wave generation from a liquid target excited by femtosecond laser has been experimentally demonstrated, and it is found that liquid has unique properties as a terahertz wave radiation source. Liquid has the comparable material density to that of solid, which means that laser pulses will interact with three orders more molecules for liquid source than for gas source. In the other hand, compared with solid, the fluidity of the liquid allows each laser pulse to interact with a fresh area of the target, which means that intense laser pulse is not an issue of material damage or degradation. These characteristics make liquid very promising for the study of high-energy density plasma and even becoming the next generation of THz source. In this paper, the influences of the shape and type of liquid target, incidence position and angle of laser beam, pulse duration and energy on THz wave generation are reviewed.