中文摘要：

《古汉语常用字字典》自出版以来已经过4次改版，它的一再改版说明了自身的不够完善。将第4版和第3版的字头作比照分析，可得出：第4版收选其第3版《难字表》中的字头共1704个，重新增加的字头共514个。第4版收字的原则是：比较常用的先秦文献和两汉文献中的字头一般都收入；虽然频繁使用、但古义和今义一样、而且现代汉语中也经常使用的字头，则不予收录。收录第4版的字头也有不妥之处：一类是收录于字典第3版《难字表》中的字头，大多不常见，字义生僻；一类是现代经常使用并且古义和今义一样的字头。

英文摘要：

The Commonly Used Dictionary in Ancient Chinese has been revised for 4 times since publishment, the repeated revision shows its imperfect. After comparing and analyzing version 4 and version 3, it comes to a conclusion that version 4 chooses 1704 hard words from version 3 and adds 514 new words. Of course, the principle of adding words lies here： the commonly used words in Pre-Qin literature and Han literature are included;the commonly used words with the same meaning in both ancient Chinese and contemporary Chinese are not included. Meanwhile, there is imperfection in the included new words in version 4： on the one hand, the hard words chose from version 3 are sometimes unusual with uncommon meanings; on the other hand, some new words are synonym in both ancient Chinese and contemporary Chinese.