The paper is devoted to study of interface matter transfer during evaporation and condensation. At the beginning different definitions of evaporation and condensation coefficients are analyzed. Then brief history of study development about mass flux density determination at evaporation and condensation is presented. The possibilities of molecular dynamics simulation concerning these processes are discussed. Then interpretation of Furukawa and Murakami (1999) [16] experimental data about determination of evaporation and condensation coefficients on helium vapor and its condensed superfluid phase (Hell) interface has been done. As a resume conclusion is made that at weak evaporation of high thermal conductivity matters as evaporation and as condensation coefficients are close to unit approximately. (C) 2011 Elsevier Ltd. All rights reserved.