Biomedical Grid is an emerging concept which couples together ideas from computational, data, access and semantic grids. Based on the requirements of the diverse biomedical community, the biomedical grid goal is to establish platform not only for computationally intensive tasks, such as protein folding or visualisation but also for expert collaboration and knowledge sharing. Knowledge sharing presents a whole new challenge for the Grid community, due to the complex security and flexibility requirements.We address one of the key problems in the biomedical grid, the problem of reliable knowledge sharing.