The substantially improved intensity measurements at wavelengths longward of the intensity peak of the microwave background are fully consistent with a Planck spectrum. The most precise data disagree with non-relativistic comptonization models for the large submillimeter excess observed by the Nagoya-Berkeley collaboration. The interpretation of such excess as dust emission at high redshifts also faces severe difficulties. Reported anisotropies on scales of several degrees and of tens of arcsec may be contributed, at least in part, by discrete sources. Just because the best experiments at cm wavelengths nave already got close to the source confusion limit, they also provide interesting information on the large scale distribution of radio sources. Polarimetry may be decisive in clarifying the origin of observed fluctuations.

Recent observations of the spectrum of the 3K cosmic background radiation (CBR) indicate that the CBR spectrum is consistent with a blackbody spectrum of T = 2.74 ±0.02K (Smoot et al. 1987). These measurements, however, were carried out in the Rayleigh-Jeans part of the spectrum, while theories predict spectral distortion in the Wien part. Therefore, we tried to observe the submillimeter spectrum of the CBR with a liq.He cooled radiometer onboard a sounding rocket. The experiment was a collaboration between Nagoya University and University of California, Berkeley.

Important progresses have been made in two fronts in the few past years.

On the theoretical ground, we have realized the importance of the quark-hadron phase transition as possibly influencing in a major way the yields of die primordial nucleosynthesis isotopes.

On the observational ground, the status of lithium as a bona-fide cosmological observable has been confirmed and its primordial abundance can be evaluated with increased confidence.