This paper explains the philosophical justifications of values on decisions in biotechnology, and compares the ethical values of animals and plants in our day-to-day activity in general and in modifying their genes in particular. We have posed some questions on the current ethical views with regard to the morality on manipulating plants. Since plants, like all other organisms, are destined to be used by humans and so far, we uphold the stability and integrity of the living system, and it is ethical to genetically manipulate plants and use them for our interests. However, we should have the moral obligation to regard their inherent value as we do for animals.