The purpose of this study is experimentally to evaluate flexural performance for connections with rib-plus precast concrete slab(RPS) to PC beam. The flexural performance by negative bending moment in this PC connections gives influence on the structure performance of connections. In this study, the main experimental parameters are the filled length of RPS and the reinforcement or not. A total of four specimens were tested and manufactured in connections under negative bending moment. As a result, it found that connections with the exception of reinforcing specimen was stiffer and stronger than connections of the prototype specimens and deformation capacity was assessed to be better. Also, the comparison of the experimental yield load and maximum load to calculated nominal load was presented to the mean 1.26 and 1.79 times, respectively. Thus, the connections for ensuring the structure safety was estimated to be reasonable thing.