  An RPC carpet covering about 10^4 m^2 (ARGO-YBJ experiment) will be installed
in the YangBaJing Laboratory (Tibet, P.R. China) at an altitude of 4300 m
a.s.l. . A test-module of about 50 m^2 has been put in operation in this
laboratory and about 10^6 air shower events have been collected. The carpet
capability of reconstructing the shower features is presented.
