本文采用生存分析的研究方法，针对最初由风险投资资助的首次公开发行的上市企业的存活时长进行研究，从而得出风险投资的长期作用和影响。本文将从两个角度对风险投资的特征进行剖析，一是专业性，二是早期性。专业性角度是研究风险投资公司的投资范围。投资于单一行业或专注于少数几个行业的风险投资公司为专业性的风险投资公司。早期性角度是研究风险投资公司进入被投资企业的阶段是否在公司发展成熟之前。在A轮融资及A轮之前进入被投资公司的为早期风险投资。本文通过文献研究选择公司成立到上市时的时间、IPO规模、所在行业表现、主承销商声誉作为控制变量，来使得研究这两个风险投资特征对被投资公司IPO之后的存活时长的影响结果更加准确。本文搜集了在Wind中国PEVC数据库中从2004年初至2018年底的所有在中国获得风险投资的事件，并且对它们进行筛选，从中选择成功IPO上市的作为研究对象。最终，有风险投资公司投资且上市的企业为1334家，其中已经合并、重组或退市的企业有105家，一直可以在股票市场上交易的公司有1229家。 本文对专业性和早期性进行建模分析的方法有两个，一个是通过非参数Kaplan-Meier方法进行生存分析，另一个是用半参数Cox比例风险回归模型方法进行生存分析。对于专业性的研究，两种研究方法的结果都显示，风险投资公司是否专注于单一或较少行业对被投资企业IPO之后的存活时长没有显著地影响。通过Cox比例风险回归模型分析，累积生存函数显示在上市初期（约前6年左右），专业性对存活时长几乎没有影响，而6年之后逐渐呈现负方向影响。对于早期性的研究，两种研究方法的结果都显示，风险投资公司早期进入被投资企业确实会对上市生存时长有显著的正方向影响，这说明投资公司早期进入被投资企业可以更早为公司提供相关支持，分享相关资源和引入更加成熟的经营理念，对公司战略等方面的制定提出合理化建议，这样有利于企业更好的发展，从而在股票市场上能够有机会被其他投资者青睐。对于控制变量，无论是在对风险投资的专业性研究还是早期性研究中，公司从成立到上市的时长与公司上市交易之后的存活时长呈现了显著的负相关关系，主承销商声誉与公司上市交易之后的存活时长呈现了显著的正相关关系。 本文通过对风险投资的直观特征-专业性和早期性进行研究，揭示了风险投资的所投行业专业程度对企业上市的长期影响不明显，而早期阶段的风险投资对被投资企业上市之后的长期影响明显。本文将有助于企业在寻找风险投资时的决策，有助于进一步的了解近年来我国风险投资领域的发展情况。同时，本文为风险投资公司和被投资公司提出了指导性建议，也为推动风险投资行业发展以及高新技术等被投资行业的发展提供了实证基础。

In this paper, the survival analysis method is used to study companies that are initially funded by venture capital about the length of time from the time of listing to delisting. Thus, the long-term role and impact of venture capital is derived. This paper divides the characteristics of venture capital into professional and early. Professionalism is the study of the investment scope of venture capital firms. Venture capital firms investing in a single industry or a few industries are professional venture capital firms; early stage refers to the stage in which venture capital firms invest in invested companies earlier --the investment phase before the A and A rounds. This paper based literature research, selects the time from the establishment of the company to the time of listing, the scale of IPO, the performance of the industry, and the reputation of the lead underwriter as the control variables , which makes the impact of the risk investment characteristics on the survival time of listed companies more realistic. This paper collected all the venture capital investment events in China from the beginning of 2004 to the end of 2018 in the Wind database and select the successful IPO listed companies as the research object. Finally, 1334 companies were selected which invested by venture capital companies and became listed companies. Among them, 105 companies have been merged or delisted, and 1229 companies can trade stocks in the stock market. In this paper, the non-parametric Kaplan-Meier method and the semi-parametric Cox proportional hazards regression model in the survival analysis model are used to analysis the professional and early characteristics. For professional characteristic research, the results of both research methods show that whether a venture capital firm focuses on a single or less industry has no significant impact on the length of time after the IPO of the invested company. The cumulative survival function through the Cox proportional hazards regression model shows that at the initial stage (listed about 6 years ago), professionalism has almost no effect on survival, and after 6 years, it gradually has a negative direction. For the early characteristic research, the results of the two research methods show that the early entry of the venture capital companies into the invested companies does have a significant positive impact on the survival time of the listed company. This indicates that the venture capital companies which enter the invested enterprise earlier can earlier provide relevant support, share relevant resources and introduce more mature business concepts, and make rational proposals for the formulation of corporate strategies. These will help the companies to develop better and thus the companies have opportunity to be favored by other investors in the stock market. For the control variables, whether in the research of venture capital professional or early characteristics, the variable that company's time from establishment to listing has a significant negative correlation with the survival time of the company's listed transactions. The reputation of the lead underwriter has a significant positive correlation with the survival time of the company's listed transactions. Through the research on the intuitive characteristics -- profession and early stage of venture capital, this paper reveals that industry profession level of venture capital has not long-term obvious influence on the listing of enterprises, and the early stage of venture capital has obvious long-term impact on the company's listing. This article will help companies to make decisions when looking for venture capital and help to further understand the development of Chinese venture capital field in recent years. At the same time, this paper puts forward guiding suggestions for venture capital companies and invested companies, and also provides an empirical basis for promoting the development of venture capital industry and the development of high-tech and other invested industries.