Guava (Psidium guajava L.) used in a various countries like India ,East Asian as herbal medicinal. Basically the aim of the study was research the various activities of guava. Guava belongs to Myrtaceae family. In India we located guava in  Bihar, Andhra Pradesh, Gujrat ,Uttra Pradesh etc. guava contains citric acid, ascorbic acid , Malic acid , tartaric acid , oleanolic acid ,tannins, ursolic acid  etc. this all different compounds present in different party of guava tree like  roots, leaves , fruits, seeds etc .Guava shows the different - different activities like anti caner activity, antibacterial activity, anti malarial activity, anti-Diarrheal activity, anti oxidant activity, anti cough activity etc. our result display the guava has various different activities which can help to treatment /therapy of different disease like cough, diarrhea, hypertension, diabetes etc.