This study aims to find the natural frequency of the floor plate structure of the arch bridge at the Islamic University of Riau (UIR), Indonesia. The main goal is to assess whether this frequency meets the Indonesian National Standard (SNI) 1725:2016 standard. In the service life, the structural capacity of a bridge construction will be affected by various load factors and environmental conditions such as earthquakes and traffic loads. Structural damage and decreased bridge performance cannot always be known from the visible condition of the bridge. In the design, the bridge has a natural frequency value inherent in the bridge structure. The frequency can change over time, which indicates a change in the bridge structure. The method used in this research is Operational Modal Analysis (OMA). OMA also called as Ambient Vibration Test is a method for estimating the dynamic characteristics of a structure (natural frequency, mode shapes, and damping ratio) based on vibrations generated from the operational conditions of the structure itself. Based on the data analysis conducted, it was concluded that the natural frequency of the bridge is in the range of 6–7 Hz, which indicates that the UIR’s arch bridge meets the natural frequency value of the bridge based on the provisions of the Indonesian National Standard Code (SNI 1725:2016).