The composting conditions of coffee grounds were examined. The results were as follows 1. Only coffee grounds piled in an outdoors environment for six months inhibited the root growth of Chinese mustard. 2. In the case of composting mixed with bark, it was necessary for the capacity ratio of coffee grounds to be below 30%, the content of chicken droppings and urea were 25g kg<-1> and 5g kg<-1>, respectively, and the composting period was more than three months.
