The chiral symmetry breaking in the presence of an external magnetic field is studied in the framework of logarithmic quark-sigma model with three flavors (u, d, s). The effective logarithmic mesonic potential is extended to strange quark and is numerically solved in the mean-field approximation. The present results show that the chiral symmetry breaking is sensitive for the strange quark flavour in the presence an external magnetic field. In addition, the effect of the free parameters is studied. A comparison with original sigma model is discussed.