隸書一體通行於秦、漢兩代，漢代隸書將「茍趨省易」的秦代隸書改變為兼具實用功能與審美價值的一種書體。不但取代小篆的地位，使用於漢代碑刻等正式場合；迄至今日，仍然廣為習書者所樂於取法。漢代隸書繼承大、小二篆的文字構成，因此，漢代隸書的文字寫法，或僅源自大篆，或僅源自小篆，或則同一文字既有源自大篆者，亦有源自小篆者。一、僅源自大篆，為「專行大篆系統者」；例如──1、「平」字之作「□」是。2、「食」字之作「□」或「□」皆是。3、「涼」字之作「□」是。4、「卿」字之作「□」或「□」皆是。5、「曾」字之作「□」是。二、僅源自小篆，為「專行小篆系統者」；例如──1、「乃」字之作「□」或「□」皆是。2、「十」字之作「□」是。3、「安」字之作「□」是。4、「辛」字之作「□」是。5、「射」字之作「□」是。三、既有源自大篆，亦有源自小篆者，則為「兼行二篆系統者」；例如──1、「七」字或作「□」，屬於大篆系統；或作「□」，則屬於小篆系統。2、「公」字或作「□」，「□」，與「□」，皆屬於大篆系統；或作「□」，則屬於小篆系統。3、「酉」字或作「□」，屬於大篆系統；或作「□」，則屬於小篆系統。4、「孟」字或作「□」，屬於大篆系統；或作「□」，則屬於小篆系統。5、「官」字或作「□」，屬於大篆系統；或作「□」，則屬於小篆系統。本文自文字構成的角度，解析漢代隸書的文字形體之二篆系統。俾在欣賞或臨寫時，心胸豁然，而無所疑滯。

Lishu, also known as the clerical script, was commonly used in the Qin and Han dynasties. Han dynasty lishu changed Qin dynasty lishu, which merely looked for stroke saving and easy writing, into a script combining practicability and beautification. During the Han dynasty lishu replaced zhuanshu, the seal script, in official occasions such as carving steles. Even calligraphers nowadays are keen on learning to write this artistic script. Han dynasty lishu inherited word constitution of the large zhuan and the small zhuan. Consequently, the word form and structure of Han dynasty lishu are found to derive either from the large zhuan or from the small zhuan. Some even derived from both. 1. Those deriving only from the large zhuan belong to“sole derivation system from the large zhuan”, e.g. 平、食、涼、卿、曾. 2. Those deriving only from the small zhuan belong to“sole derivation system from the small zhuan”, e.g. 乃、十、安、辛、射. 3. Those deriving from both the large zhuan and the small zhuan belong to “double derivation system from the large and small zhuans”, e.g. 七、公、酉、孟、 官. This study explores the two-zhuan systems of Han dynasty lishu by analyzing word constitution. The purpose is to help understand Han dynasty lishu when appreciating or model copying this type of calligraphic works.