Superconducting properties were studied on high quality superconductors \(Ba_{x}(NH_{3})Fe_{2}Se_{2}\) (\(T_{c}\) = 39 K) and \(Sr_{x}(NH_{3})Fe_{2}Se_{2}\) (\(T_{c}\) = 44 K) prepared by intercalating Ba/Sr atoms into tetragonal \(\beta\)-FeSe by liquid ammonia. The elongated c-axis and almost unchanged a-axis of \(Ba_{x}(NH_{3})Fe_{2}Se_{2}\), comparing with \(\beta\)-FeSe, suggested an unchanged intra-\(Fe_{2}Se_{2}\)-layer structure and the \(T_{c}\) enhancement is due to a 3D to 2D-like Fermi surface transformation. The superconducting coherent lengths \(\xi\)(0), Ginzburg-Landau parameters \(\kappa\) and penetration depths \(\lambda\)(0) obtained from the extrapolated lower and upper critical fields \(B_{c1}\)(0) and \(B_{c2}\)(0) indicates that both compounds are typical type-II superconductors. The temperature dependence of 1/\(\lambda^{2}\)(T) of \(Ba_{x}(NH_{3})Fe_{2}Se_{2}\) deduced from the low field magnetic susceptibility shows a two-gap s-wave behaviour with superconducting gaps of \(\Delta_{1}\) = 6.47 meV and \(\Delta_{2}\) = 1.06 meV.