Abstract: A dc/dc converter control scheme based on chaos is proposed, which can improves electromagnetic compatibility of dc/dc power supply. Firstly an expression of Logistic map is derived, which can generated chaotic sequences with controllable amplitudes. Then a chaotic sequence is applied to perturbs reference current parameter in hysteresis current control scheme. Power spectrum of inductance current is spread and electromagnetic interference on switching frequency and its harmonic frequency is reduced. Simulation results show that the new scheme can improve electromagnetic compatibility of the dc/dc converter.