Аннотация:The domain of admissible parameters of A 0620-00 = V616 Mon has been obtained in terms of the model for tidally distorted K stars with a partial eclipse by the outer dark portions of accretion disk. It has been concluded that the mass of the second component is 3 M$_sun$ \le M$_x$ \le 5.3 M$_sun$, thusby confirming the expected existence of black hole component of the system; the accretion disk radius R$_d$ is variable; often the disk nearly fills the Roche lobe; in the quiet state the Roche lobe filling by K star is 0.74 \le μ \le 0.94; the system inclination is 75\deg \le i \le 83\deg.