Equations for the fluctuation correlation in an incompressible shear flow are derived on the basis of kinetic theory, utilizing the two‐point distribution function which obeys the BBGKY hierarchy equation truncated with the hypothesis of “ternary” molecular chaos. The step from the molecular to the hydrodynamic description is accomplished by a moment expansion which is a two‐point version of the thirteen‐moment method, and which leads to a series of correlation equations, viz., the two‐point counterparts of the continuity equation, the Navier‐Stokes equation, etc. For almost parallel shearing flows the two‐point equation is separable and reduces to two Orr‐Sommerfeld equations with different physical implications. Solution of an eigenvalue problem for the Blasius boundary layer is obtained in a certain parallelism to the classical stability theory, and is used for predicting the transition Reynolds number of a “quiescent” Blasius flow in which thermodynamic fluctuations alone are the initiating mechanism. Also, the calculated spatial growth rate of fluctuation agrees with the Schubauer‐Klebanoff experiment, which gives an account of unexplained experimental evidence that the fluctuation complex (turbulence bursts plus the Tollmien‐Schlichting wave), as a whole, obeys a certain linear theory.