We investigated the in-plane spin reorientation transition (SRT) in a two-dimensional ferromagnetic/antiferromagnetic system by using Monte Carlo simulation based on the Heisenberg model. The temperature-driven SRT in the ferromagnetic layer is studied for the case of that the antiferromagnetic layer has an uniaxial in-plane or fourfold in-plane anisotropy. For the case of an uniaxial in-plane anisotropy in the antiferromagnetic layer, the ferromagnetic layer spin processes a $90\ifmmode^\circ\else\textdegree\fi{}$ in-plane SRT from perpendicular to parallel direction of the anisotropy. For the case of a fourfold in-plane anisotropy in the antiferromagnetic layer, the ferromagnetic layer spin processes a $45\ifmmode^\circ\else\textdegree\fi{}$ in-plane SRT. We also studied the Curie temperature of the ferromagnetic layer and find a significant reduction in the Curie temperature as the Curie temperature is close to the SRT temperature.