In the present paper, we have developed a modified analytic embedded atom method potential for chromium. To solve the problem of a negative Cauchy relation for body-centered cubic metal at zero Kelvin temperature, a modification term is added to the total energy. Compared with available interatomic potentials, the present one is easier to be extended because of its analytic form. The fitted or input parameters are all well reproduced, and the properties beyond the fitting range (such as Cauchy relation, melting point and self-interstitial atom formation energies) are also well predicted. We have also studied the relation between the stacking faults energy and screw dislocation core structure with different potentials. Especially, only our potential predicts a compact core structure, which agrees with the results obtained by density functional theory calculations.