We propose a primeval baryon isocurvature model in the context of the Affleck-Dine ( AD ) baryogenesis mechanism .
Quantum fluctuations of the AD field during inflation produce fluctuations in the baryon number .
We obtain a model which gives both the appropriate baryon to entropy ratio of the order 10 ^ { -11 } and the gaussian baryon isocurvature perturbation of the order 10 ^ { -3 } at the break of the spectrum 1 \mbox { Mpc } with the steep spectrum n = -1.5 on large scales > 1 \mbox { Mpc } .