The statistical considerations in determining evidentiary standards for biomarker qualification is tied integrally to roles biomarkers play in drug development – in stratification, prevention, screening or diagnosis of diseases; in prognosis; in prediction or therapy-related risk management; and in therapy monitoring or surveillance among others. A biomarker or a panel of biomarkers can be used in target validation, early compound screening, assay selection, patient selection or as surrogate endpoints (IOM biomarkers report, 2010). The presentation will start with biomarker definition and its challenges, followed by types of biomarkers and their role in drug development. The evidentiary consideration will be discussed with respect to statistical design and analysis issues. Some concluding remarks will be provided.