  A sky monitoring at gamma ray energy E > 0.6 TeV has been performed by the
full coverage Extensive Air Shower detector ARGO-YBJ, located in Tibet at 4300
m of altitude. We monitored 135 galactic and extragalactic gamma ray sources in
the sky declination band from -10 to +70 degrees for 424 days, detecting the
Crab Nebula and Mrk421 with a significance respectively of 7.0 and 8.0 standard
deviations. For a set of 11 AGNs known to emit in the TeV energy range, the
search has been performed in time scales of 1, 10 and 30 days in order to study
possible flaring activities. Significant emissions has been observed from
Mrk421 in the time scales of 10 and 30 days, during June and March 2008, when
the source had a strong activity also observed in the X-rays waveband. The
analysis of the background has revealed the existence of a significant excess
of the CR flux in two localized regions of angular size 10-30 degrees, in
agreement with previous indications.
