The progress of research on and existing problems with polyvinyl alcohol (PVA) fibers with high tensile strength and high elastic modulus in improving crack resistance and toughness of concrete are summarized. In terms of crack resistance improvement, PVA fiber improves the resistance to plastic cracking and ultimate tensile strength of concrete. Projects in hydraulic engineering, hydropower engineering, and water transport engineering in China have begun using PVA fibers to improve crack resistance of concrete. In terms of toughness improvement, research mainly focuses on the effect of fiber content, concrete strength, the reinforcement ratio, and other factors in the flexural toughness of concrete. The theory of design of toughening materials, mechanisms of crack formation and propagation, and constitutive equations of PVA fiber-reinforced concrete should be further investigated.