Viscum album var. coloratum (mistletoe) is considered as one of the endangered plant species in Korea. Our objective is to restore its population and multiplication of plant by ex situ method. In this research we explored the maximum germination (in vitro) of freshly harvested and stored seeds of mistletoe collected in different time intervals. Ex vitro germination after artificial inoculation on the branches of Prunus mume in different physiological conditions was also monitored. The research revealed that the lately harvested seeds (Feb. and March 2014) were superior over early harvested seeds (Nov. 2013 and Jan. 2014) of mistletoe due to the higher percentage of germination (above 93%). According to the data, it is also revealed that the survival and germination rate of mistletoe seeds decreased with the increase in storage duration. In ex vitro germination, the fluctuated temperature of a glass house in natural condition enhanced (four fold) the rate of germination on the branches of Prunus mume than the constant temperature condition in the glass house.