A voltage compensation type pixel circuit of an AMOLED display device includes a driving transistor serially connected to a light emitting element between high-potential and low-potential power lines to drive the light emitting element in response to a voltage supplied to a first node, a first program transistor for supplying a data voltage of a data line to a second node in response to a scan signal of a scan line, a second program transistor for supplying a reference voltage from a reference voltage supply line to the first node in response to the scan signal of the scan line, a merge transistor for connecting the first and second nodes in response to a merge signal of a merge line, a storage capacitor connected between a third node and the second node interposed between the driving transistor and the light emitting element to store a voltage which corresponds to the data voltage in which the threshold voltage is compensated, and first and second reset transistors for initializing at least two of the first, second, and third nodes to an initialization voltage of an initialization voltage line in response to a reset signal of a reset line.