A pure Mendelsohn triple system of order v, denoted by P MT S(v), is a pair (X, B) where X is a v-set and B is a collection of cyclic triples on X such that every ordered pair of X belongs to exactly one triple of
MT S(v) and these A i s form a partition of all cyclic triples on Y . It is shown in [3] that there exists an O L P MT S(v)for v ≡ 1, 3 (mod 6), v > 3, or v ≡ 0, 4 (mod 12). In this paper, we shall discuss the existence problem of O L P MT S(v)s for v ≡ 6, 10 (mod 12) and get the following conclusion: there exists an O L P MT S(v) if and only if v ≡ 0, 1 (mod 3), v > 3 and v = 6.