In ICs design,undertaking ESD protect,level shift,circuit drive etc.the function's circuit constitute an I/O circuit.With Reliability design of I/O circuit increase IC's reliability.Characteristics that the paper design from the circuit designing,layout designing,and package designing etc.the stage set out.Reliability each stage contents that design,summarize some design important points and design rules.Bring upped the adoption I/O circuit,seal to pack,PCB in conjunction with the design's method,increasing I/O circuit reliability.