This paper is concerned with a linear quadratic optimal control problem of delayed backward stochastic differential equations. An explicit representation is derived for the optimal control, which is a linear feedback of the entire past history and the expected value of the future state trajectory in a short period of time. To obtain the optimal feedback, a new class of delayed Riccati equations and delayed-advanced forward-backward stochastic differential equations are introduced. Furthermore, the unique solvability of their solutions are discussed in detail.