  In this paper, deep holes of Reed-Solomon (RS) codes are studied. A new class
of deep holes for generalized affine RS codes is given if the evaluation set
satisfies certain combinatorial structure. Three classes of deep holes for
projective Reed-Solomon (PRS) codes are constructed explicitly. In particular,
deep holes of PRS codes with redundancy three are completely obtained when the
characteristic of the finite field is odd. Most (asymptotically of ratio $1$)
of the deep holes of PRS codes with redundancy four are also obtained.
