In a standing-up motion assist system for assisting a care receiving person, a care belt includes a first holder that holds a neck part or a back part of the care receiving person, a second holder that holds a lumbar part of the care receiving person, a third holder that connects the first holder and the second holder and holds armpits of the care receiving person, a second connector located at a chest of the care receiving person, and a first connector that connects the first holder and the second holder. A pulling mechanism is connected to the second connector and pulls the second connector. A controller controls the pulling mechanism so as to pull the second connector in a forward and upward direction with reference to the care receiving person, and, thereafter, pull the second connector in a backward and upward direction with reference to the care receiving person.
