Observation of transition region fine structures with SOHO/SUMER

We present a preliminary analysis of two quiet Sun transition region areas observed with the SOHO/SUMER spectrometer, using lines from oxygen, nitroge n and silicon. The average quiet Sun physical parameters are studied as a f unction of line intensity. Systematic variations of line position and width with increasing intensity are found. A large number of small-scare active points have been observed, and preliminary analysis of the physical propert ies and dynamics of these active features is presented. A jet-like structur e, found in an active point, is also investigated and its velocity along th e line of sight determined.