Abstract: The possibility of estimating mechanical properties of steels by small punch tests instead of conventional tests has been proved by a number of researchers. In the present paper, small punch test technique was illustrated briefly, and research on how to measure ductile brittle transition temperature(or fracture appearance transition temperature) and fracture toughness( K IC or J IC ) of steels was reviewed and analyzed in detail. The feasibility of using this miniature specimen technique to evaluate damage of service exposed materials was discussed.