The analysis of the optical variability of 3C 345 along with the apparent superluminal motions in the milliarcsecond jet suggests a connection between these forms of activity.The optical variability of the quasar 3C 345 is presented including our 18-year photographic observations and all published data by 1984. The extrapolated moments of ejection of milliarcsecond jet components from nucleus coincide with the initial phases of the "slow" optical flares. The prediction about the arising of a

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... radiocomponent based on such treatment was confirmed later on. Some evidence of similar connection for the N-galaxy 3C 120 is given.It has been discovered in recent years that some extragalactic objects have apparent superluminal motions in their milliarcsecond jets. It is obvious that independently of the concrete physical interpretation of this phenomenon it represents an evidence of nuclear activity. Consequently this phenomenon may be connected with the variability of the optical continuum source. The object most suitable for studying such a relationship is the quasar 3C 345. This superluminal object is the best-observed both by VLBI technique and by several optical monitoring programs which revealed very high degree of its optical variability ( in the B-band).