本论文以2013年受到社会极大关注的韩磊摔童案为研究对象，对案件涉及的三个理论问题——故意杀人罪的认定问题、主观恶性和人身危险性的区分、对定罪量刑的影响、“不是必须立即执行”的问题——先从法理上进行阐述，后结合案情具体分析。试图通过理论结合实际的探讨回应社会现实，为故意杀人罪的研究尽微薄之力。本文共分五章：第一章主要介绍了选案的理由，基本的案情，法院的判决要旨，以及由案件所引发的理论问题。由本案所研究的案例，可以引申出三个争议问题：一是故意杀人罪的认定问题。二是主观恶性和人身危险性的区分，对定罪量刑的影响。三是“不是必须立即执行”的问题。第二章讨论本罪的定性问题，分为两条。第一条讨论韩磊是否出现认识错误，以致出现故意杀人罪和过失致人死亡罪定罪的争议。笔者根据辩护意见逐步证明韩磊有杀人动机、韩磊没有出现认识错误、韩磊构成故意杀人罪。第二条讨论通过和河南摔童案的对比，讨论韩磊是否应判处故意伤害致死，通过理论上分析故意杀人罪和故意伤害（致死）罪的界分，我们得出区分两罪应以结果定罪，韩磊应判故意杀人罪。第三章讨论主观恶性和人身危险性的关系、定义以及分别对定罪量刑的影响。通过分析我们认为，主观恶性和人身危险性是相互独立的关系。主观恶性是已然状态，属于主观方面主要用于评价罪犯犯罪当时的心理事实，是对罪过心理机制的揭示。对定罪、量刑均有影响。而人身危险性指再犯可能性。只对量刑有影响。第四章讨论死刑“不是必须立即执行”的理由。通过对以往案例的总结，我们发现此标准有很大模糊性、任意性。最高人民法院应尽早研究制定故意杀人、抢劫、毒品、故意伤害等死刑较多的几类犯罪适用死刑的指导意见为司法实践提供有力指导。最后探讨了死刑立即执行的消极条件，受正义价值和人道主义的限制。第五章结束语，总结全篇文章，得出相应结论。

In this thesis, we take the great community concerning Han Lei’s fell child case in 2013 as the research object, aiming to discuss three involved theoretical problems: the determination of intentional homicide, the distinction between subjective evil and personal dangerousness and its influence on conviction and sentencing, and the problem of “the immediate execution of a criminal punishable by death is not deemed necessary”. For this, we elaborate upon it in terms of legal principle firstly and make a concrete analysis with case files and materials secondly, trying to bring more rational thinking to the theory study and judicial practice.This paper is divided into five chapters as following:The first chapter mainly introduces the reasons for case selection, the basic situation of the case, the main content of the judgment of the court and the theoretical and practical issues arising from the case. Three issues shall be derived from the selected case: First, how to determine the crime of intentional homicide; second, how to distinguish subjective evil and personal dangerousness and how it shall influence the conviction and sentencing; third, how to judge the situation of “the immediate execution of a criminal punishable by death is not deemed necessary” The second chapter discusses the qualitation of this crime, which is divided into the following two aspects. First, we discuss whether a cognition error existed on Han Lei, leading to a controversy between intentional homicide and intentional lethal injury. According to the defense opinion, we gradually prove the facts that Han Lei has murdering motive, he did not have cognition error and he committed the crime of intentional homicide. The second point lies in the comparison with a fell child case in Henan, we discuss whether Han Lei should be sentenced with the crime of intentional lethal injury. Through the theoretical analysis of boundary between intentional homicide and intentional lethal injury, we concluded that the two crimes should be convicted using the results as standards and Han Lei should be sentenced with the crime of intentional homicide.In the third chapter, we discuss the definition of subjective evil and personal dangerousness, their relationship and their influence on conviction and sentencing. Through the analysis, we hold the opinion that subjective evil and personal dangerousness is independent from each other. Subjective evil is a accomplished state, belonging to the subjective aspect and mainly used in the evaluation of the psychological fact of the criminal at the time. It is a reveal to the psychological mechanism and affect both on the conviction and sentencing. However, personal dangerousness refers to the recidivism, affecting only on sentencing.In the fourth chapter, we discuss the justification for “the immediate execution of a criminal punishable by death is not deemed necessary”. Through the summary of past cases, we find the standards are very fuzzy and arbitrary. The supreme people's court should study and formulate guiding opinions on the requirements for death penalty on several kinds of crimes as soon as possible, including intentional homicide, robbery, drugs and intentional injury. Finally we discuss the negative requirements for “death sentence with immediate execution”, which should be restricted by the justice value and humanitarian. Chapter 5 is the conclusion, which summarize the article as a whole and draw a corresponding conclusions.