To solve the problems of work efficiency and dusting related to the environment in relation to a powder dropping and displaying method which is predominant as a method of drawing a line on a playground or turf with a line powder, and to meet the demand for a line powder sufficiently satisfying conditions which enable a user to clearly draw a line on turf and to easily eliminate the line because there is a growing tendency to turf a stadium and a playground.

A calcium carbonate-based powder composition for a wet line is provided which is agitated with water on the spot and used so that a clear line can be drawn on a playground, turf or other places requiring a line or display without generating dust in lining.