Almost every financial crisis in history is the outbreak of systemic financial risks. After each financial crisis, many researchers devote themselves to exploring the causes of systemic risks and so far they have reached a lot of meaningful conclusions. This paper provides an overview of researches on this topic based on qualitative research method and manages to (i) sort out the key driving causes that are most commonly identified in the researches;(ii) summarize the general evolution mechanism; and (iii) explore core risk sources of systemic financial risks. We use grounded theory to review 194 articles published between 1978 and 2017 in the databases such as Elsevier, JSTOR, SSRN, Springer, ProQuest and China Knowledge Network (CNKI). First, we find eight key driving causes of systemic financial risks, namely:excessive financial innovation, failures in financial regulation and supervision, global economic structural imbalance, shortcomings of economic development model, contradictions of capitalism, lax monetary policy, failures of corporate governance and risk management, and investor sentiment. Second, according to the statistics, about 54.84% views regarding the key driving causes are directly related to the formation of "asset price bubble" and these opinions cover 3 key role players in the systemic risk forming mechanism evolution framework:macro-policy, market mechanism and microscopic individual behavior. On this basis, we build an evolution mechanism framework for analyzing the causes of systemic financial risks with asset price bubble as the core. Third, we highlight the importance of financial innovation to both systemic risk and the formation of asset price bubbles.
