Rice is a very important food in the world, a staple food for more than half of the world's population, especially Asia. People in Asia plant rice crops, more than 90% of the world's rice crops which are grown. In the current technological era the conditions of agricultural crops such as rice can be monitored rapidly from the air. This study aims to classify the age of rice plants based on cartesian coordinate position vectors from the extracted basic, red, green, and blue color spectrum of reflectance. The research was done by taking the image of rice plants based on age classification and Furthermore, the extracted values of each spectrum is normalized and then be plotted on cartesian coordinate The result obtained from this research is the position vector of normalized RGB values be able to differentiate the age classification of rice plant. The each vector position represented a single group of age classification. The three vector units i.e. red, green and blue figure every axis on the 3 dimensional Cartesian coordinates. This research concluded that the 3-dimensional position vector method of cartesian coordinates, can classify the age of rice plants.