  The distance energy of a simple connected graph $G$ is defined as the sum of
absolute values of its distance eigenvalues. In this paper, we mainly give a
positive answer to a conjecture of distance energy of clique trees proposed by
Lin, Liu and Lu [H.~Q.~ Lin, R.~F.~Liu, X.~W.~Lu, The inertia and energy of the
distance matrix of a connected graph, {\it Linear Algebra Appl.,} 467 (2015),
29-39.]
