Abstract: Lie detection of Backster System from U.S.A has been applied in Chinese court as a new technique since 1993. It is successfully used in both civil and criminal cases which had never been done in other countries. Efforts were made to improve the system to meet with Chinese culture. The reliability, validity and distinguishability were verified at a high level by a large sample of more than 300 Chinese subjects in three years. Relevant issues are discussed in order to make greater progress in practice work, such as the estimating level in the judgment of lying or honesty, error elimination and so on.

Key words: Backster system, court technique, value system, indefinite zone