Significance of confinement in covariant quark model.

We studied significance of confinment in covariant model of quarks. For this we studied ana-lytical property of quarks’ diagram’s. Calculations were based on two point quark’s loop with scalar quarks. We investigate ordinary local loop case and case with nonlocal crest factor with confiment and without it. To calculation real and imaginary part was used ?-method. We estimated matrix elements for that cases. It was shown that in case with cofinment, loop is real, smooth and without any cusp in the quarks-producing threshold. The conclusion done in two ways, first, by the standard technique of Cauchy's theorem and analytic prop-erties of the loop, and, secondly, using the original transformations of the integral into the form of the dispersion representation.