A total coloring of a graph
G is a function
such that no adjacent vertices, edges, and no incident vertices and edges obtain the same color. A
k-interval is a set of
k consecutive integers. A cyclically interval total
t-coloring of a graph
G is a total coloring
a of
G with colors 1,2,...,t, such that at least one vertex or edge of
G is colored by i,i=1,2,...,t, and for any
, the set
is a
-interval, or
is a
-interval, where
dG(x) is the degree of the vertex
x in
G. In this paper, we study the cyclically interval total colorings of cycles and middle graphs of cycles.