Microcystis and Anabaena are two major genera of bloom-forming cyanobacteria. The way in which the two cyanobacteria regulate their own morphology and physiological characteristics to maintain rapid growth is to explain the maintenance of two cyanobacteria blooms. In this study, the response of growth, morphological and photosynthetic characteristics of Microcystis (FACHB-905) and Anabaena (FACHB-82) to temperature changes were measured, and the trade-offs relationship between growth and these characteristics were analyzed. The results showed that the cell diameter of Microcystis decreased under high temperature, but the growth rate did not decrease under high temperature. These indicates that Microcystis could increase the growth rate by reducing the cell size under high temperature conditions. The cell diameter and the chain length of Anabaena changed significantly with the change of temperature. The chain length decreased significantly and the growth rate did not decrease under high temperature conditions, which suggests that Anabaena might regulate its morphological characteristics to maintain the high growth rate. At the same time, the specific growth rate of the two algae has a certain relationship with the photochemical activity, indicating that the two algae can adapt to the temperature change by weighing the relationship between their own morphology, photosynthetic characteristics and growth rate to obtain the best growth status. This study will be helpful to improve our understanding for the growth mechanism of cyanobacteria.