Clinical trials are experimental studies with human subjects in which various limitations and variables exist by their nature. As a preparatory stage for designing clinical trials in Oriental medicine, this study considers a virtual protocol to show guideline regarding tasks necessary when writing a trials protocol. Clinical trials have many difficulties in planning, procedure, and interpretation of results, and these may be influenced by various biases that are difficult to predict and eliminate. To deal with these issues, clinical trials need a collaboration between medical experts and biostatisticians from the beginning, through the entire trial, until the final analysis. Therefore, the first stage of clinical trials is to write out a trial plan among the experts in each field to derive the best design for the trial.