The pentasyllabic regulated verse of Liu Zhangqing 劉長卿 (ca.718-ca.790) has long been ambivalently appraised as using ＂identical imagery＂ 意象雷同 on the one hand and initiating ＂diction creativity＂ 語出獨造 on the other. This ambivalence reflects two trends of the time, namely rigid compliance with conventions and gradual changes in the pentasyllabic regulated verse of the Dali 大曆 Period (766-779) represented by Qian Qi 錢起 (ca.710-ca.780) and Liu Zhangqing. The external causes for the occurrences of ＂identical imagery＂ are twofold: 1) the intimacy among the poets and 2) their shared creative environment. The internal cause was the narrowing of poetic themes to three main traditional categories, namely ＂farewell,＂ ＂sending and dedicating,＂ and ＂lodgings on a journey.＂ As these poets inherited and continued the High Tang mainstream poetic styles and practices, the imagery in their poems evolved and was refined. ＂Diction creativity＂ refers to innovation in wording and structure of the verses. One evident phenomenon was the deviation from conventional morphological practice and even from the regular grammar of pentasyllabic verse. Such practices included: 1) the uncommon morphological structure of common imagery and diction; 2) the broadened rhythmic span of the semantic caesural pause between the second and third character in a pentasyllabic line; and 3) the creation of one poetic image in each five-character line. Its significance lies in the profound exploration of the expressive potential of pentasyllabic regulated verse, which enhances the vividness of the poetic form of regulated verse. This trend anticipated the pursuit for ＂completing versification in five characters＂ in the later development of pentasyllabic regulated verse.