Urban green space is a fundamental and attractive element of cities around the world all through the year. Selecting species resistant to dryness is an essential decision for planting them in the urban green space in arid and semi-arid regions. One of the most important experiments to introduce new plants in new regions is phenology of different species. In this study, the phonological characteristics of Quercus infectoria have been identified using two different methods namely descriptive and analytical digital photography. In total, ten trees in the campus of Isfahan University of Technology have been fortnightly monitored for two years. The time of phonological phenomenon of each tree was registered in information forms, and different parts of the tree were photographed with a digital camera. The spectral spectrum of the leaf and fruit of the tree were produced and the colours were analyzed in RGB system, with radiometric resolution of 2⁸ for each colour. For determining the effect of temperature on colour changing in time, the 2G-RB index was used. According to the descriptive observations the flowering and leafing occurs in the end of March. In colour changing diagrams the intersection of green channel with red in late October exhibits a revolution in leaves colour. In the fruit colour diagrams, the whole of transmuting stages from flower to fruit was detected and the emergence time of these stages was gained. Also, the correlation between temperature and 2G-RB index for both leaf and fruit is significant and can be used as a means for monitoring phenology of the tree due to climate changes in future studies.