Narlikar, J. V.2012-03-072012-03-071990-03-12http://hdl.handle.net/11007/897The binary stars have provided testing sites for gravity theories ranging from the Newtonian law of gravitation in the last two centuries to the theory of relativity and other gravity theories today. The binary pulsar in particular holds out the promise of testing strong field effects of gravity, rli~ii~~j!~li~llii~j! between relativity and other theories. This review discusses the conceptual and observational issues involved in this process of testing.enBinary starsGravity theoriesRelativityArticle