Abstract: Bio-statistics is the important branch of statistics and is related to medical field. Also it plays an important role in the field of research. The main role of statistics in research is to designing a research, analyzing data and draw meaningful conclusions. The meaningful conclusion can be drawn by using proper statistical tests. Statistics also helps to reduce large volume of raw data which must be suitably reduced so that the same can be read easily and can be used for further analysis. This article covers the brief outline of data, qualitative data, and quantitative data. Also give a brief outline of measures of central tendency (location), measures of variability (dispersion) , statistical inference(parametric and non-parametric tests) and give brief outline of sample size calculations.[4]