The ability to produce stable, high-quality nanocrystal (NC) inks in solution with high-throughput is a critical issue in the development of low-cost solar cells. In this paper, a continuous flow method is developved for synthesizing shape-controled, mono-disperse and solution stable chalcopyrite colloidal I-III-VI NC (e.g.CuInSe2) inks with potential scalability. It was found that the morphologies of the NCs were dependent on compositions. The NC morphology changed from spherical to hexagonal to trigonal with increasing In content, where trigonal morphologies synthesized at high temperature yielded chalcopyrite NCs.