The present invention provides an array substrate and a display device, to solve the problem of low testing precision due to significant difference between characteristics of TFTs in the detecting region and TFTs in the display region in the prior art. The array substrate comprises a display region and a dummy pixel region provided in the periphery of the display region, wherein, at least one detecting unit is provided in the dummy pixel region, each detecting unit comprises one second pixel unit, one thin film transistor is provided correspondingly to each second pixel unit, and respective electrodes of each thin film transistor provided correspondingly to the second pixel unit are connected to an external test device through test lines, respectively.