Abstract: A comparative study was made on the characteristics of water relation (e.g. transpiration rate, transpiration efficiency, water potential etc.) of 9 Masson pine provenances from July 1988 to January 1989. The results indicate that the characteristics of water relations have definite cor-relationship with the growth and have a relatively higher genetic stability. It is shown that the mechanism of drought-resistance Of Masson pine may be attributed to its good drought-avoidance and drought-tolerance besides its strong water-absorbing ability. Owing to the above differences, the different provenances of Masson pine have the dissimilar drought-resistance. It was further observed that good provenances Of Masson pine(e.g. the provenances in southern zone) were characterized by lower transpiration rate and water saturation deficit, higher transpiration efficiency and critical w.s.d, and higher drought-resistance, which result a less influence of water stress on the growth and a higher increment. Consequently, the 9 provenances may be classified into 3 types and 5 sub-types on the bases of the characters of water relations, using the method of cluster analysis