Abstract: From the network structure of relations in guarantee network, we apply network analysis and the data of listed companies from 2003 to 2017 on the Shanghai and Shenzhen stock exchanges to analyze guarantee network risk contagion mechanism. The results show that negative shock or the increase of relations significantly exacerbates risk contagion. But negative shock can only lead to risk contagion through guarantee chain, which demonstrates that the path of guarantee network risk contagion has relationship transitivity, which de- pends on the relation of guarantee chain. In the process of guarantee network formation, the ineffective guarantee contract and asymmetric information caused by lack of legal environment and the rigid restriction of guarantee contracts or implicit guarantee of state-owned enter- prises caused by low financial marketization are drivers underlying enterprises' motivation to join the guarantee chain and this will finally lead to risk contagion in guarantee network. Furthermore, the negative shock has a great influence on these enterprises with a high be- tweenness and those highly related enterprisess tend to gain prosperity or sufer loss jointly. Therefore, the government should improve in- stitutional environment and visual supervision of network structure of guarantee behavior among listed companies.

Key words: guarantee network, risk contagion, relations, network structure