An embodiment of the present disclosure provides an organic electroluminescent transistor array substrate, including a substrate, and a gate layer, a gate insulating layer, a semiconductor layer, a source layer, a pixel defining layer, an electroluminescent layer and a drain layer formed on the substrate, wherein, the source layer and the drain layer are located in different levels, the source layer includes plural source electrode units corresponding to sub-pixel units respectively, the pixel defining layer includes plural pixel defining units corresponding to the source electrode units respectively, and the respective source electrode units are embedded within the pixel defining units corresponding thereto.