In order to provide an interactive interface that arouses a user's sympathy and realizes a continuous interaction having much information, an interactive system of providing the interactive interface of performing an interaction with a user includes a computer and a measurement device of measuring a signal related to a user's speech. The computer calculates a first feature amount indicating feature of a user action in the speech of the user, based on the signal measured by the measurement device, calculates a second feature amount that is a control value of a response action to the user performed by the interactive interface, based on the first feature amount, calculates a control time of adjusting a timing of controlling the response action depending on the type of the response action, and controls the interactive interface, based on the second feature amount and the control time.