Phenology, the science of biological events can be considered as the nature’s thermometer since all phenological events are specifically linked to natural/ seasonal events. Thus, a change in phenology of a species clearly indicates the change in physical factors like the climate. Several studies have pointed out the earlier flowering events for mid and high latitudes and lengthening of the growing season due to climate change (Waltheret al., 2002; Root et al., 2003). Phenological shift and declining yield are evident and well-studied in case of different crop plants since they are directly related to the food security of nations and livelihood of the people. But in the case of other plants which are endemic and rare, the studies associating phenology and climate variability are lacking. The current study intends to explore the association between phenology of endemic plant species and climatic factors in New Amarambalam Reserve Forest in North Kerala. It is proposed to study the effect of climate variability on the phenology of the endemic species of New Amarambalam Reserve Forest. The changes in biological processes such as leafing, flowering and fruiting and their depending faunal diversity will be examined. Knowledge on endemic species’ response to climate variability in the case of Western Ghats, global biodiversity hotspot can be enhanced.