[1] The rupture history of the 20 April 2013 Mw 6.6 Lushan (China) earthquake is constrained by inverting waveforms of local strong motion, teleseismic broadband body waves, and long-period surface waves. This earthquake ruptured a blind thrust fault oriented N210°E (along the Longmenshan fault zone) and dipping 40° to the NW. The inverted slip distribution is heterogeneous, dominated by a slip patch with a roughly right triangular shape, which spans a depth range of 5–20 km and accounts for two thirds of the total seismic moment (8.9 × 1018 N m). The rupture initiated roughly at the middle of the triangle's hypotenuse and, during the first 4 s, propagated mainly in along-strike and downdip directions, toward a peak slip of 1.2 m. Despite a large number of fatalities and economic loss, the estimated static and apparent stress drops of the Lushan earthquake are 1.5 MPa and 0.35 MPa, considerably low with respect to other similar intraplate earthquakes.