DescriptionThe goal of this dissertation is analytical investigation of large families of automorphic L-functions on GL2. With a view towards potential applications in Analytic Number Theory, we investigate families of holomorphic modular forms, but additionally averaged over the nebentypus - characters and over the levels. We establish orthogonality in such a family in the limited range in the form of large sieve type inequality. Further we investigate non-vanishing at the central point of the corresponding L-functions and give a bound for the sixth moment for ¡1(q)-family, consistent with Lindelöf hypothesis on average.