Electromyographic activities of the cricothyroid muscle (CT) and sternohyoid muscle (SH) in the production of intonation pattern in Tokyo dialect were analyzed with special reference to the effects of focus. Correlation analysis between F0 and CT activity showed that the effect of CT activity on F0 rise is greater for the first pitch peak within an utterance than for the later pitch peaks. This phenomenon may be related at least in part, to the so-called down-step phenomenon in Tokyo dialect. As for the SH, its activity varied with placement of focus. It is speculated that this change may be associated with a change in laryngeal state accompanying an expansion or reduction of pitch range due to focus.