作为唐律的十二篇目之一，《诈伪律》是专门针对欺诈和伪造行为的法律规定。 “诈”、“伪”字义相近，却适用不同刑罚。诈，从言，是违背信义、用虚假语言以牟利的欺诈行为。“伪”，从人，是私铸、伪造器物或文书的作伪行为。这些犯罪行为或侵害国家官僚运转体系，或侵扰社会礼治、管理秩序，或伤害当事人人身利益，因而需要法律条文予以规范。《诈伪律》独立成篇于《魏律》，集大成于《唐律》。根据皇权、官僚运转秩序和社会经济生活需要的不同，汉唐明三朝法律在行为人量刑及处罚上斟酌损益，依诈伪行为的危害性增减刑事责任。

唐律第372条“诈称官捕人”主要惩治的是冒充官员及诈称奉官司之命追捕当事人的行为。《汉书》即有记载诈称官者处以斩刑或弃市的案例，明律无可考，只有“诈称内使等官”条与之相近。“诈称官捕人”条于唐代适用较少，此与唐鱼袋制、考课制、拘捕制度运行状况有关，犯罪行为的成本高，定罪概率大。作为正义的缉捕执法者，亦有追捕罪犯中的职务犯罪与渎职行为，此与缉捕者滥用职权，畏权势、缉捕不力，缉捕行为滋多有关。“诈称官捕人”条虽非处罚捕者行为的律文，但亦是朝廷为保障缉捕活动有序进行而设。

唐律第387条“证不言情及译人诈伪”主要惩治证人不言实情和译语人翻译诈假之犯罪。根据行为主体不同，犯罪情形与量刑规范亦有所异。“证不言情”罪中，被告人资格限定为“据众证定罪”范畴，证人亦不可为“于律得兼容隐”和“老小笃疾”之人。就译语人而言，律文主要对译人妨碍司法审判正确性的行为作出量刑。唐廷亦会在有翻译需要时，采取回避与事件有利害关系的译语人、重要事件多人翻译、命译人签字画押等措施，来保障翻译行为的准确性。汉唐明时期“证不言情与译人诈伪”罪在立法规范、犯罪主体主观心态、量刑标准上有诸多异同。

As one of the twelve parts of the Tang law, the law of fraud and forgery was a special legal provision for fraud and forgery. "Fraud" and "false" had similar meanings, but they were applicable to different penalties. Deceit, from words, was a deceitful act that went against faith and used false words for profit. "Forgery" refered to the forgery of artifacts or documents. These crimes either infringed on the operation system of state bureaucrats, or disturbed the rule of social etiquette, management order, or infringed on the interests of social economic property, or harmed the interests of all parties. Therefore, it needs to be regulated by legal provisions. The law of deceit and falsehood was an independent part of the law of Wei, which was a collection of the law of Tang. According to the different operation order of imperial power and bureaucrats, and the needs of social and economic life, the three dynasties of Han, Tang and Ming considered the profit and loss in the sentencing and punishment of the actor, and increased or decreased the criminal responsibility according to the harmfulness of fraud.

Item 372 mainly punished the behavior of pretending to be an official and pursuing the party under the order of a lawsuit. "Deceitful officials" was easy to be confused with "deceitful officials" and "deceitful lawsuits". It seemed that "deceitful officials arrest people" should be listed in the chapter of the law of arrest and death. In the book of Han Dynasty, there were records of cases in which a person who pretended to be an official is punished by beheading or abandoning the city. There was no test in the Ming Dynasty law, but the article "pretending to be an internal envoy or other official" was similar to it. The article of "pretending to be an official catcher" was rarely applied in Tang Dynasty, which was related to the operation of Tang fish bag system, examination system and arrest system. The cost of criminal behavior and material cost were high, and the probability of conviction was high. As a just law enforcer, there were also duty crimes and dereliction of duty in the pursuit of criminals, which was related to the abuse of power, fear of power, ineffective arrest and more arrests. The article of "pretending to be an official to arrest a person" was not a law to punish the behavior of the person arrested, but it was also set up by the court to ensure that the arrest activities were carried out in an orderly manner.

Item 387 mainly punished the crimes of the witness not telling the truth and the translator's deceitful translation. According to the different subjects, the crime situation and sentencing norms were also different. The defendant's qualification was limited to the category of "conviction according to public testimony", and the witness couldn’t be the person of "being compatible with the law" and "the old and the young". Due to the limitation of the scope of application of the law, the low status of the witness and the possibility of being tortured, the judicial practice of the crime of testifying without expressing feelings is less. As far as the translator was concerned, the law text mainly measured the punishment for the translator's behavior that hindered the correctness of the judicial trial. Tang Ting would also take measures to ensure the accuracy of translation when necessary, such as avoiding the translators who had an interest in the event, translating the important events and ordering them to sign their autographs. In the period of Han, Tang and Ming, there were many similarities and differences in the legislative norms, the subjective mentality of the subject of the crime and the sentencing standards.