Watermelon (Citrullus lanatus) as a crop with important economic value, is widely cultivated around the world. The heat shock protein 70 (HSP70) family in plant is indispensable under stress conditions. However, no comprehensive analysis of watermelonHSP70family is reported to date. In this study, 12ClHSP70genes were identified from watermelon, which were unevenly located in 7 out of 11 chromosomes and divided into three subfamilies. ClHSP70 proteins were predicted to be localized primarily in cytoplasm, chloroplast, and endoplasmic reticulum. Two pairs of segmental repeats and 1 pair of tandem repeats existed inClHSP70genes, andClHSP70sunderwent strong purification selection. There were many abscisic acid (ABA) and abiotic stress response elements inClHSP70promoters. Additionally, the transcriptional levels ofClHSP70sin roots, stems, true leaves, and cotyledons were also analyzed. Some ofClHSP70genes were also strongly induced by ABA. Furthermore,ClHSP70salso had different degrees of response to drought and cold stress. The above data indicate thatClHSP70smay be participated in growth and development, signal transduction and abiotic stress response, laying a foundation for further analysis of the function of ClHSP70s in biological processes.