In this work, we give a partial positive answer to the question concerning
the set-valued quasicontraction proposed by Amini-Harandi (Appl. Math. Lett.
24:1791-1794 2011). By a useful lemma, we prove a fixed point theorem for
the set-valued quasi-contraction, which extends the range of contraction
constant in result of Amini-Harandi from [0, 1/2) to [0, 1/3? 3). Also,
we give a new simple proof for the result of quasi-contraction type proposed
by Haghi et al. (Appl. Math. Lett. 25:843-846 2012). Finally, a
counterexample and a theorem concerning cyclic set-valued mapping are given,
which improve some recent results.