Due to its excellent ferroelectric, piezoelectric and pyroelectric properties, polyvinylidene fluoride (PVDF) polymers have been intensively investigated. Researches and developments on the phase structure in PVDF polymers in recent years from relevant literatures are summarized and reviewed. It is pointed out that molecular structures in five crystalline formations are different from each other. Some new methods and ideas of preparation or enhancementβ phase in PVDF polymers in recent years have been analyzed. Based on their advantages and disadvantages, the future research works are also suggested.