在python中，預設情況下是無法顯示中文的，如下程式碼：

import matplotlib.pyplot as plt  
  
# 定義文字框和箭頭格式  
decisionNode = dict(boxstyle = "sawtooth", fc = "0.8")  
leafNode = dict(boxstyle = "round4", fc = "0.8")  
arrow_args = dict(arrowstyle = "<-")  
  
# 繪製帶箭頭的註解  
def plotNode(nodeTxt, centerPt, parentPt, nodeType) :  
    createPlot.ax1.annotate(nodeTxt, xy = parentPt, xycoords = 'axes fraction', xytext = centerPt, textcoords = 'axes fraction', va = 'center', ha = 'center', bbox = nodeType, arrowprops = arrow_args)  
  
def createPlot() :  
    fig = plt.figure(1, facecolor='white')  
    fig.clf()  
    createPlot.ax1 = plt.subplot(111, frameon = False)  
    plotNode(U'決策節點', (0.5, 0.1), (0.1, 0.5), decisionNode)  
    plotNode(U'葉節點', (0.8, 0.1), (0.3, 0.8), leafNode)  
    plt.show()  
  
createPlot()  
 

得到影象如下：

產生中文亂碼的原因就是字型的預設設定中並沒有中文字型，所以我們只要手動新增中文字型的名稱就可以了

手動增加如下程式碼

from pylab import *  
mpl.rcParams['font.sans-serif'] = ['SimHei']  

import matplotlib.pyplot as plt  
  
from pylab import *  
mpl.rcParams['font.sans-serif'] = ['SimHei']  
  
# 定義文字框和箭頭格式  
decisionNode = dict(boxstyle = "sawtooth", fc = "0.8")  
leafNode = dict(boxstyle = "round4", fc = "0.8")  
arrow_args = dict(arrowstyle = "<-")  
  
# 繪製帶箭頭的註解  
def plotNode(nodeTxt, centerPt, parentPt, nodeType) :  
    createPlot.ax1.annotate(nodeTxt, xy = parentPt, xycoords = 'axes fraction', xytext = centerPt, textcoords = 'axes fraction', va = 'center', ha = 'center', bbox = nodeType, arrowprops = arrow_args)  
  
def createPlot() :  
    fig = plt.figure(1, facecolor='white')  
    fig.clf()  
    createPlot.ax1 = plt.subplot(111, frameon = False)  
    plotNode(U'決策節點', (0.5, 0.1), (0.1, 0.5), decisionNode)  
    plotNode(U'葉節點', (0.8, 0.1), (0.3, 0.8), leafNode)  
    plt.show()  
createPlot()