东汉中后期出现的马融、郑玄等人的经注，为后世学术的发展奠定了基础。后世以经学注疏为主导的学术形态，正是形成于此时。若要了解这一时期学术演进的动因，不能仅仅关注平面的制度设置，还应深入汉王朝的行政实践，辨析行政运作与学术形态变化之间的关系。汉王朝的行政实践中，用于选拔官员的策问制度，对经学发展尤其具有影响力。汉和帝永元十四年的策问改革，因此就显得特别关键。这项改革是汉章帝时期崇尚古学学风的自然延续，其重视章句、家法的改革，推动了古学的流行，并在以下三个方面深刻地改变了当时的学术形态：其一是经书文本开始标准化；其二，新型的小章句形式的经注开始流行；其三，经注开始注重内在统一性和体系性。与此同时，小章句形式的经注书籍促进了新的经典学习方式的成熟，通过独立阅读注本来研读经典。许多经注书籍因其完备性而开始突破门派限制，在更大范围内流传，并逐渐经典化。这或许就是郑玄那一代人因何出现的部分原因。

The annotation of Confucian classics emerged in the middle and later Han dynasty by Ma Rong, Zheng Xuan et al. laid the foundation of mainstream form for future academics. In the administrative practice of the Han court, the system of Cewen (question on current affairs) for official selection was influential on the studies of Confucian classics. Thus the reform on the Cewen system in the fourteenth year of the Yongyuan reign (C. E. 102) became critical in this process. The reform continued the classical style of learning in the period of Emperor Zhangdi of Han which emphasized syntactic and semantic analysis as well as learnings handed down from master to disciple. Meanwhile, the reform changed the academic form at that time profoundly in the following three aspects: first, the texts of Confucian classics became standardized; second, the new form of minor syntactic and semantic analysis came into style; and thirdly, the annotations began to pay attention to internal unity and system. And a new learning style that cracking the classics by reading the annotating texts solely was then promoted. Many books of annotation began to break the limitation of factions, spread in a larger range, and gradually turn into classic because of their completeness. This might be part of the reason the generation of Zheng Xuan emerged.