A Closed Environmental Experiment Facility (CEEF) is a facility with an objective of the implementation of various experiments in order to practically study appropriate conditions to persons' long-term living in a closed space without any intake and discharge of materials. The detail design has been accomplished, and its construction is scheduled to launch within the fiscal year 1994. It will be operated by Institute for Environmental Science with the financial support of the Japanese Government.The Facility contains habitat module, animal feeding module, plantation module and their life support systems. The Plantation module is a facility where plants are cultivated to provide a person with food by hydroponics. At the present time seven kinds of plants are nominated as candidates to be cultivated there; Rice, Soybean, Sesame, Tomato, Komatsuna (Japanese tender-green mustard), Potato and Soba.Preliminary experiments were carried out to obtain the data necessary for the future hydroponic cultivation in CEEF, since some of these candidate plants have not been cultivated throughout the whole process from seeding to harvesting by hydroponics.This paper mainly describes the intermediate results of the preliminary experiments.