In the last decade many buildings such as multipurpose buildings, malls, auditoriums, sports halls which have long-span building floor structure. Various research results indicate that in general long-span concrete floor structures have a fundamental frequency of less than 7 Hz. This will risk a resonance if this floor receives dynamic loads of people jogging to follow the song with a frequency of 2-3 Hz. This research was conducted to numerically analyze the long-span building floor model using SAP2000, to determine the fundamental frequency and maximum displacement of the floor structure model. It was also investigated how to increase its fundamental frequency and reduce the maximum displacement. The results have shown that the numerical analysis of the plate model long-span floor building using SAP2000 produces a fundamental frequency of 5.19 Hz. Model III with Reinforcing double equal angles (84x37x10x2.5) steel truss provides the best results, increases the fundamental frequency to be 7.93 Hz, and with a variety of static and dynamic loads, decreases the value of the displacement and far from the allowable displacement.