In order to improve the accuracy, operability, and rapidity of the identification of natural and artificial shark fins, a facile method based on responses to repeated heat and cold treatments and/or tissue structure was establised in this work.. The results of the repeated heat and cold treatments showed that the natural shark fins had obvious characteristics of repeated heat-contraction and cold-expansion, and the optimum conditions were two cycles of 5-min heat and 30-min cold treatments. To further validate the feasibility of these conditions, the data of repeated heat and cold treatments on different parts of the shark fins and different types of natural shark fins were statistically analyzed. Results showed that the data had good precision, small error, good accuracy, and followed a normal distribution, and that the mean values were representative. Additionally, the artificial shark fins had different characteristics, repeated heat-expansion and cold-contraction. The tissue morphology results showed that the natural shark fin needle was in the shape of an irregular concentric ring, and that the annular arrangements were relatively homogeneous, a unique characteristic of annual ring formation in fish. However, the artificial shark fins did not have this characteristic. Therefore, the difference of microstructure between the natural shark fins and the artificial shark fins was obvious. In general, the heat-contraction and cold-expansion method and tissue morphology analysis are rapid, easy, and accurate methods to distinguish between natural and the artificial shark fins.