In 1982, N. Miller [5] showed a weighted $L^p$ boundedness theorem for pseudo differential operators with symbols $S^0_{1.0}$. In this paper, we shall prove the pointwise estimates, in terms of the Fefferman, Stein sharp function and Hardy Littlewood maximal function, for pseudo differential operators with reduced symbols and show a weighted $L^p$-boundedness for pseudo differential operators with symbol in $S^m_{ ho,delta}$, 0{$leq}{delta}{leq}{ ho}{leq}1$, ${delta}{ eq}1$, ${ ho}{ eq}0$ and $m=(n+1)( ho-1)$.