Bond default incidents frequently in 2018 more than ever，especially for some private enterprises or listed companies，and also defaults generally occur in various industries. Base on the research of cases，this report finds macroeconomic downturn and tightening of credit are the major default market features，as well as the mutual conduction between liquidity and risk preference under the tense international situation. Most default companies show aggressive investment style，profit decline，governance issues，contingent liability and unbalanced debt structure. On this basis，this report constructs a analysis framework of default conduction，and proposes implications for risk warning.