Abstract: The present disclosure provides use of sweetpotato IbSAP15 gene in regulating leaf shape and flower shape of sweetpotato. Compared with the control, Ipomoea batatas cv. Xuzishu 8, IbSAP15-overexpressing lines have more deeply incised blades, dehiscent corollas, and higher ornamental value. In the present disclosure, overexpression of the sweetpotato IbSAP15 gene in sweetpotato can deepen leaf incisions, make trumpet-shaped corollas dehiscent, and change leaf shape and flower shape of sweetpotato. The present disclosure is suitable for developing sweetpotato germplasms with different leaf shape and flower shape and promotes ornamental flowering/foliage sweetpotato breeding.