\documentclass[12pt]{standalone}

\usepackage{tikz}
\usepackage{ctex}

\begin{document}
\begin{tikzpicture}

\scoped[<-,every node/.style={circle,draw}]
\node[color=red] {1}
    child {node {2}}
    child[color=red] {node {3}
        child {node {4}}
        child[color=black] {node {5}}};

\end{tikzpicture}
\end{document}