Environment has blessed us with various kinds of plants. Some of them uses as resources of medicines as it is called medicinal plant. In Bangladesh medicinal plants are also known as Ayurveda, Homeopathy and Unani. Experts says medicinal plants can be very useful in the fight with recent pandemic which is Covid-19. As we know health of a body depends on its immune system, so it is important to keep immunity stronger. Strong immune system can be influential to any infectious virus, bacteria and pathogens. On the other hand, inactive one can get easily infected with virus and other illness. There are certain medicinal plants which reinforce our immunity. Therefore, classification of these medical plants is very important. For this classification we have collected leaf images for six different classes which’s local names are Darchini, Tulshi, Tejpata, Sojne, Neem, Pathorkuchi. In this article we introduced a famous algorithm for classification named CNN (Convolutional neural network). We used CNN (Convolutional neural network) to recognize the plant from leaf images and got 95.58% accuracy. In future infectious virus can appear which can be more threatening than others, our research will help people to know about immune system and medicinal plants which reinforce our immunity, so that they can fight with diseases and viruses.