Directed logic circuit is a paradigm which employs the optical switch network to perform the logical operation. The status of each switch in the optical network is determined by an electrical Boolean signal applied to it. The operation of each switch is independent of the operations of other switches in the network and the operation result propagates in the network at the speed of light. Therefore, the directed logic circuit has a very high operation speed and the overall latency of the logic circuit is very small. Silicon microring resonator is an attractive structure to construct optical directed logic owing to its outstanding performances, such as compact size, ultra-low power consumption and CMOS-compatible process. Therefore, the directed logic based on silicon microring resonators is easy to realize large-scale integration and low-cost manufacture in a CMOSphotonics foundry. Directed logic circuits based on silicon microring switches including OR/NOR, AND/NAND, XOR/XNOR, encoder, decoder and half-adder have been proposed and demonstrated by our research group. Our recent research on directed logic circuits based on silicon microring resonators is reviewed and new development in this topic is introduced.