1,3-butadiene(C4H6) is important for the oxidation and pyrolysis of long-chain hydrocarbons and the formation of soot. In this study, the laminar burning velocities of 1,3-butadiene/O-2/He mixtures were measured using the spherically propagating flame at initial temperature of 298 K, initial pressure of 0.5-1.5 MPa and equivalence ratio of 0.8-1.5. The laminar burning velocities of 1,3-butadiene/air mixtures were also measured at initial temperature of 298-398 K, initial pressure of 0.1-0.5 MPa and equivalence ratio of 0.7-1.6. Comparison was made between experimental and calculated results of USC MECH II and AramcoMech 3.0. Both mechanisms show good prediction on laminar burning velocities of 1,3-butadiene/air mixtures, but only AramcoMech 3.0 mechanism gives good prediction on the measured laminar burning velocity of 1,3-butadiene/O-2/He mixtures at higher pressures. Sensitivity analysis was made to analyze the effects of temperature, pressure and equivalence ratio on reaction pathways. Difference between two mechanisms was observed in the sensitivity of C4H6+ O reactions, and pathway analysis was performed to further study the reaction pathways. Consumption pathways are almost the same for 1,3-butadiene/air and 1,3-butadiene/O-2/He mixtures. The two mechanisms have consistent opinions of C4H6+ H reactions, but totally different opinions on the pathway of C4H6+ O reactions. It can be found that more C3H6 is present in USC MECH II, leading to the laminar burning velocity with USC MECH II are lower than that of AramcoMech 3.0.