Phenology is an important ecological feature that can be influenced by many abiotic aspects. For example, the decrease in temperature along an altitudinal gradient display a fundamental role in the phenophases it affects the life cycle and activity of insects and herbivores, therefore, mountainous regions are great sites to perform studies to help the understanding of the reproductive cycle of plants. In this work, the phenological cycle and leaf damage rate caused by herbivores in Trifolium repens L. were observed, among three different altitudes (1.700, 2.000 and 2.400 m) in the Itatiaia National Park, from June to August of 2021 and statistical analysis were performed using linear mixed effects models. Preliminary results show that altitude affected vegetative phenophases (number of open leaves, shoots and abscissions) and herbivory (P < 0.01). The highest altitude sampled stands out for having a less open and damaged leaves, and for being the only altitude without any flowering events. However, due to low intensity of this phenophase at other altitudes, it wasn’t possible to determine if altitude is in fact affecting flowering. Nevertheless, the influence of growing season climate on phenology is often observed in transplanting experiments, in which at lower altitudes plants typically develop earlier than those in their high altitude native sites. As for the damage caused by herbivores, it was expected that the highest altitude would present a lower damage rate than the others sites, since it is known that environmental conditions of higher altitudes (such as decreased temperature) can reduce the aptitude of various insects.