Аннотация:We present results of observations of NGC 4151 obtained from 1986 to 1991 with the TV scanner of the 6-meter telescope. The shape of the profile of HeIIλ4686 line, averaged over periods of 2-3 months, appear to change during these 5 years of observations. The broad component of Hβ however does not show similar variations during this period. We discuss the possible reasons which may be responsible for this effect.