| In this work, EH36 TMCP steel plate was applied to study the mechanical behavior of the welds by shielded metal arc welding (SMAW) process. The microstructure of the TMCP steel plate treated by on-line accelerated cooling consists of a refined ferrite and intergranular pearlite. The mixed microstructures composed of mianly grain boundary ferrite, Widmanstatter ferrite and acicular ferrite together with some microphases are in the weld metal. The coarse-grained HAZ is composed of a large amount of lower bainite with upper bainite. Fined-grained HAZ consists of mainly refined ferrite and bainite. The fusion zone has a higher hardness, the other regions regardless of postweld heat treatment. The low carbon equivalent of the TCMP steel results in hte less increase in hardness in the HAZ. The result reveals an obvious difference in impact values between L and T specimens. The effect of tempering at 600℃/2hr has a less influence on the microstructures and mechanical properties of TMCP steel welds.