Based on piecewise monotone interval maps and linear coupling, we study order patterns of spatiotemporal chaos. The forbidden patterns are found to arise mainly from the reduction of curve intersections due to time invariance of chaotic maps. It is proved that linear couplings may destroy the time invariance, and create the conditions for increasing intersections. We analyze the effects of chaotic map, coupling strength and coupling number order patterns. Simulation results and illustrative examples all confirm the correctness of the theoretical results.