WEKA is a machine learning tool in Java, which provides inbuilt algorithms for data analysis. We used two data sets: Iris dataset, Twenty newsgroups. We had to run classifiers like 1. Naive Bayesian, Multinomial Naive Bayesian for small data sets of Iris; 2. j48 for Iris decision trees. 3. Support Vector Machine in form of SMO. For Twenty Newsgroup we had to use above classifiers, and after that, used K means for clustering. We studied algorithms, gained practical knowledge of data mining. It was a project done under our mentor A. K. Singh sir of CSED, MNNIT Allahabad.