余亮罡, on 2011年01月03日 13:31, wrote: > I just do not know how to change the font size,could you tell > me that? Thank you ! Here's a small example. You can either keep around the ylabel from when you first create it: import matplotlib.pyplot as plt lbl = plt.ylabel("foo") lbl.set_size(25) If you already have the labels on an axes: ax = plt.gca() lbl = ax.yaxis.get_label() lbl.set_size('x-small') Note that ax.get_ylabel() only gets you the string of the label, which is why you have to use ax.yaxis.get_label() to get an instance of the matplotlib.text.Text object in order to change its size. hope that helps, -- Paul Ivanov 314 address only used for lists, off-list direct email at: http://pirsquared.org | GPG/PGP key id: 0x0F3E28F7