In this dissertation, the structure, dynamics and evolution of two quiescent prominences were studied. Quiescent prominences are large structures and mainly associated with the quiet Sun region. For the analysis, the high spatial and temporal cadence data from the Solar Dynamic Observatory (SDO), and the Solar Terrestrial Relations Observatory (STEREO) were used. The observations from two different directions were combined and the prominence in 3D were studied. In the study of polar crown prominence, the prominence flows on limb were mainly investigated and its association with on-disk brightenings were found. The merging of diffused active region flux in the already formed chain of prominence caused the several brightenings in the filament channel and also injected the plasma upward with an average velocity of 15 km/s. In another study, the triggering mechanism of a quiescent tornado-like prominence was investigated. Flares from the neighboring active region triggered the tornado-like motions on the top of the prominence. Active region field contracts after the flare which results in the expansion of prominence cavity. The prominence helical magnetic field expands and plasma moves along the field lines which appear as a tornado-like activity. These observational investigations led to the understanding of structure and dynamics of quiescent prominences, which could be useful for theoretical prominence models.