To improve durability of a mat main body by erecting wall bodies on an edge part under surface of a base board of respective blocks formed by dividing the mat main body, connecting mutual lower end parts of the opposed wall bodies of the adjacent blocks by connecting bodies, and setting the lower ends of plural columns erected on an under surface of the base board and the connecting bodies to an almost equal height.

Respective blocks 5 formed by dividing a mat main body have a lattice plate-like base board 6, columns 7 erected on its under surface and a grass-leaf body such as the artificial lawn, and the blocks adjacent to each other by leaving a clearance 9 are arranged. Wall bodies 10 are continuously erected over the total length of the clearance 9 on an under surface of an edge part of the base board 6. Lower end parts of the opposed wall bodies 10 of the adjacent blocks 5 are also connected to each other by plural connecting bodies 11. The respective connecting bodies 11 are formed in a plan view elliptic plate shape which is long in the lengthwise direction of the clearance 9 and whose thickness is almost equal to a thickness of the wall bodies 10, and the lower ends of the respective connecting bodies 11 are arranged in a height position equal to the lower ends of the respective columns 7. Therefore, even if used over a long period of time, the mat main body is not cut along the clearance.