Hi, > Without glues between Chinese characters it's quite easy > to have overfull or underfull boxes in a line ... I don't know Chinese, but please try, for example \XeTeXlinebreaklocale "zh_CN" \XeTeXlinebreakskip=0em plus 0.1em minus 0.01em \XeTeXlinebreakpenalty=0 (line ending should be %LF) Best regards, Akira