A system of multimodality-appended rich media comments is provided. The system includes a server and an electronic device. The electronic device includes a network access module, at least one sensor and a processing unit. The network access module communicates with the server. The at least one sensor senses a user's behavior in a recording mode to obtain a sensing data. The processing unit performs an application to provide a source medium, wherein a rich media comment function of the application can be activated to provide multiple interactive objects for selection and then trigger the recording mode. The application uploads the sensing data to the server after the recording mode finishes. The server analyzes the sensing data and accordingly modifies the selected interactive object, combines the source medium with the modified interactive object into a rendered medium, and then delivers the rendered medium to the application.