Some of the construction weathered away, while plants growing in the walls have accelerated the decay, according to the recent report, which cited a survey last year by the Great Wall of China Society.
"Even though some of the walls are built of bricks and stones, they cannot withstand the perennial exposure to wind and rain," Dong Yaohui, a vice president of the society, was quoted as saying.
"Many towers are becoming increasingly shaky and may collapse in a single rain storm in summer."