The damping ratio on aluminum alloy single layer spherical reticulated shells with plate-type joints was studied by field measurement. For an aluminum alloy spherical latticed shell with a planar dimension of 45m×45m and a rise of 2.86m, a total of 11 test cases were planned and 160 acceleration damped free vibration signals were collected on site under human-induced excitations as well as 6 vibration signals under environmental excitations. Using the method of analytical modal decomposition (AMD) combined with the Hilbert transform, natural frequencies and modal damping ratio of the structure were identified. Statistic studies were carried out and an average damping ratio of 4% was suggested for this kind of structures. Finite element (FE) models were established using the suggested damping ratio, and the nodal dynamic responses given by numerical analysis showed good consistency with those given by the tests. The damping ratio given here could give a basis for the revision of the current code and provide a reference for the structural dynamic analysis and engineering design.