Determinations of the water vapor concentration in Venus's atmosphere from Vega 1 and 2 were carried out by means of the moisture analyzer VM-4. The analyzer includes two sensitive elements: heating water-absorbing sensor based on LiCl for measuring the temperature of the condensation point (-30¿ to +30¿), and a coulombmetric sensor for measuring volume water vapor concentration (0.01--0.2%). The ranges of water concentration measurements by both sensors complement each other and partially overlap. The instruments were placed on the landing devices of the spacecraft. The measurements were carried out at altitudes of 62--25 km above the surface of the planet. Two vertical water vapor concentration profiles were measured in Venus's night atmosphere.