Aminobutyric acid (GABA) is a ubiquitous non-proteinaceous amino acid, and widely distributed in species of microorganisms, animals and plants. It has many health-promoting benefits including lowering blood pressure, improving memory, inhibiting cancer cell proliferation, enhancing immunity, reducing sleeplessness, etc. In this paper, we mainly reviewed the research progress of jujube (Ziziphus jujuba Mill.) on sleep improvement, introduced the discovery of GABA in jujube fruit, and discussed its determination methods. Firstly, we speculated that jujube might contain GABA by analyzing literatures of jujube improving sleep. And then, our preliminary survey results proved that jujube contained GABA, and daily consumption of 61g dried fruit (about 3 jujube fruits) might get sufficient GABA to produce the effects of improving sleep. It suggested that GABA was likely to be an important functional component of jujube fruit. The advantages and disadvantages of present GABA determination methods were also analyzed, and we put forward that it was necessary to optimize HPLC method combined with OPA precolumn derivatization for GABA determination. Finally, the perspective on the research trend of GABA in jujube fruit was discussed, and this review might provide some critical information for research of GABA in jujube fruit.