Technological complexity is an inevitable challenge for latecomer firms aiming to upgrade themselves. Applying a perspective of firms within sectoral system of innovation, this paper studies the catch-up efforts of the leading Chinese pharmaceutical firms in the past few decades. The findings show that technological complexity tends to lengthen catch-up process, raise capability requirement, require more networking, and demand complicated institution design, which asks for a more evolutionary catch-up strategy with self-investment into system capability and network competence. The findings of this article provide references for catch-up efforts in other industries of technological complexity.