Let f be a twice continuously differentiable self-mapping of a unit disk satisfying Poisson differential inequality |△f(z)|≤B·|Df(z)|2 for some B>0 and f(0)= 0.In this note,we show that f does not always satisfy the Schwarz-Pick type inequality 1-|z|2/1-|f(z)|2≤C{B),where C(B)is a constant depending only on B.Moreover,a more general Schwarz-Pick type inequality for mapping that satisfies general Poisson differential inequality is established under certain conditions.