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We present the results of low- and high- resolution spectroscopic and multicolour photometric observations of two early-type emission-line stars, AS 78 and MWC 657. They were identied by Dong & Hu (1991) with the IRAS sources 03549+5602 and 22407+6008, respectively, among many other sources displaying a very strong infrared excess, V (25) 8 mag AS 78 is recognized as a photometric variable for the rst time. A large near-IR excess radiation is detected in AS 78 and conrmed by new, higher-quality, data for MWC 657. Signicant variations in the Balmer line proles are detected for both objects. Modelling of the Balmer line proles of AS 78 obtained in 1994 yields the following parameters of the star and its wind: Te 17 000 K, log Lbol/L 4.0, _ M 10 6 M yr 1 .T he photometric and new spectroscopic data indicate that the star's Te increases with time, while the stellar wind changes its structure. Distances towards both objects are estimated on the basis of their radial velocities and the galactic rotation curve. Consideration of dierent options about the nature and evolutionary state of both objects leads us to suggest that they are binary systems

Spectroscopy and photometry of the emission–line B–type stars AS 78 and MWC 657