The National Institute of Environmental Research (NIER) in South Korea publishes the user guidelines for the effectiveness testing of wood preservatives regarding the approval of biocidal substance and biocidal products on March 28^th, 2023. This guideline is based on the Korean Standards ‘KS M 1701:2018/Annex B/(Regulation) methods for effectiveness testing of wood preservatives’ to help field users understanding. It includes remarks of performing effectiveness testing, testing process, validation of effectiveness testing. The Korean Standards ‘KS M 1701’ is available from http://standard.go.kr.