  Understanding the different mechanisms of galaxy assembly at various cosmic
epochs is a key issue for galaxy evolution and formation models. We present
MASSIV (Mass Assembly Survey with SINFONI in VVDS) in this context, an on-going
survey with VLT/SINFONI aiming to probe the kinematics and chemical abundances
of a unique sample of 84 star-forming galaxies selected in the redshift range z
~ 1-2. This large sample, spanning a wide range of stellar masses, is unique at
these high redshifts and statistically representative of the overall galaxy
population. In this paper, we give an overview of the MASSIV survey and then
focus on the spatially-resolved chemical properties of high-z galaxies and
their implication on the process of galaxy assembly.
