Provided is a system construction assistance system including: a system definition input unit that inputs a system definition including at least a designation of a component using a component definition that is capable of including a field definition and a setting definition about a setting to a constituent element associated with the field, and an assignment definition related to assignment of a constituent element to a field included in the component; and a setting assignment unit that associates a constituent element with a field in a designated component, based on the system definition and the component definition, and assigns a setting to a constituent element constituting a target system, by reflecting a setting content defined with respect to the field in the constituent element associated with the field.