It was found at the scene of quarantine that a total of 537 chickens of a batch of 4 752 chickens were died in Shenzhen city on July 9，2016，of which the mortality rate was 11.30%. An urgent investigation was carried out by quarantine officers，including asking the consignor，viewing on the spot，animal autopsy，laboratory detection，epidemiological analysis，and so on. It was considered that the death was closely related to the temperature，and the cause of this death event was confirmed as Heat stress syndrome. Further analysis showed that there was a positive correlation between the number of died chickens and the temperature in this market. By the estimation and analysis of the loss of this incident，reasonable suggestions were put forward for long-distance transportation under high temperature weather，providing a reference for reducing economic losses and reducing the risk of epidemic transmission.