This study is concerned with 18 precast concrete beam-column connections incorporating embedded steel box-section using Finite Element (EF) modelling. The variables considered were: length and width of the embedded steel member. The results indicate that connection containing a wider flange of the embedded member can resist more vertical loading. Also, the deflection at ultimate load increases as the width of the embedded steel section increase. Generally, there are a few design methods available in the codes; this study also evaluates the available design formulas using FE simulation results and the data from other researchers. From the evaluation and the analysis it was shown that twice the width of the embedded width should be taken as the effective width of the connection when the PCI (Precast Concrete Institute) design equations are used.