Compact Groups are excellent laboratories to test the importance of 
interaction for triggering nuclear activity. Their high galaxy densities,
similar to those observed in cluster cores, together with their low velocity 
dispersions maximize the chance of encounters. Gravitational interaction 
between their members it is clearly shown by morphological and kinematical 
perturbations, the presence of intergalactic gas emission in X-rays , 
the existence of tidal features such as tails or shells and the perturbed 
distribution of molecular and atomic gas. To carry out this work we need a 
large enough well defined sample of groups. Hence, we have defined a complete 
sample of Compact Groups obtained from the list of 92 groups with concordant 
redshift in the catalog by Hickson. The catalog can be considered complete 
until mu<=4.4 and the z distribution also shows a cutoff at about z=0.045, 
which is the limit that we will adopt here. We have therefore selected all 
the groups with mu<=4.4 and z<=0.045, which gives a well defined statistically 
complete sample of 65 groups. We will present optical spectroscopy for 
42 galaxies belonging to the sample and their preliminary nuclear 
classification by us diagram and the [NII]/Ha ratio to distinguish between 
photoionization produced by OB stars (HII-region) or by a non-thermal 
continuum (AGN). Adding the 68 galaxies, belonging to the sample and 
classified by Coziol et al (2004), we have 110 analized galaxies.