In the previous study, a new method for transplanting zostera japonica which doesn't require much diving work was developed. This method is to put a biodegradability sheet close to living areas of zostera japonica and to move the sheet to the destination after zoster japonica grows enough on the sheet. Although the applicability of the sheet was already confirmed through a field survey, it was also observed that some zostera japonica are removed from the sheet after transplanting the sheet. In this study, laboratory experiments were conducted to clarify the requirements for zostera japonica to remain certainly on the sheet. The results of the laboratory experiments show that when the sheet is moved, more than 5cm of shoot roots need to remain and the moved sheet should be attached firmly to the destination ground.