Fibre-matrix interface is known to have contribution to the mechanical performance of fibre-reinforced composite by its potential for load transfer between the fibre and the matrix. Such load transfer is of great importance in dentistry when a post is used for fixing a ceramic crown on the tooth. In this study, a pull-out test was carried out to analyse the interfacial properties of a steel fibre embedded in a polyester and epoxy matrices. It was found that the fibre-matrix interface is debonded on the whole embedded length when the fibre stress reached the debonding stress. Then, the fibre stress fell down to the initial extraction stress required to pulling out the debonded fibre from the matrix. Both debonding stress and initial extraction stress initiated a linear increase with the implantation length after the debonding stress reached horizontal asymptotes. To analyse the fibre-matrix load transfer before debonding, an analytical shear-lag model was adopted to in this test conditions. Fitting the experimental results with the analytical model provided the interfacial shear strength. By considering the Coulomb friction at the fibre-matrix interface during the fibre extraction process, an analytical model which considers Poisson’s effects on both fibre and matrix, was developed. In this model, knowledge of the initial extraction stress of the fibre provides the residual normal stress at the fibre-matrix interface. Fibre-matrix interface is known to have contribution to the mechanical performance of fiber-reinforced composite by its potential for load transfer between the fiber and the matrix. Such load transfer is of great importance in dentistry when a post is used for fixing a ceramic crown on the tooth. In this study, a pull-out test was carried out to analyze the interfacial properties of a steel fiber embedded in a polyester and epoxy matrices. It was found that the fiber-matrix interface is debonded on the whole embedded length when the fiber stress fell down to the initial extraction stress required to pull out the debonded fiber from the matrix. Both debonding stress and initial extraction stress initiated a linear increase with the implantation length after the debonding stress reached horizontal asymptotes. To analyze the fiber-matrix load transfer before debonding, an analytical shear-lag model was adopted to this test conditi ons. Fitting the experimental results with the analytical model provided the interfacial shear strength. By considering the Coulomb friction at the fiber-matrix interface in the fiber extraction process, an analytical model which considers Poisson’s effects on both fiber and matrix, was developed. In this model, knowledge of the initial extraction stress of the fiber provides the residual normal stress at the fiber-matrix interface.