Abstract: The plate specimens with V cut pre-cracked were fabricated and the test using acoustic emission(AE) to monitor the process of tensile fracture of plate specimens was designed. Associated with fracture mechanical behavior during tensile and some IR images, the correlations of some AE parameters with fracture process of the two kinds of specimens were deeply analyzed, the AE feature during tensile fracture and its description of damage process was studied. The results showed that the AE energy, hits, counts, amplitude, peak value of frequency contents and so on. during tensile fracture for plate specimens could describe the corresponding damage process. This further proved the feasibility of AE monitoring and early warning application on steel structures, and some conclusions about AE parameters were gained.