Technological complexity is an inevitable challenge for latecomer firms aiming to upgrade themselves. Applying a perspective of firms within a sectoral system of innovation, this chapter 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 the catch-up process, raises capability requirement, requires more networking, and demands complicated institution design, which asks for a more evolutionary catch-up strategy with selfinvestment into system capability and network competence. The findings of this chapter provide references for catch-up efforts in other industries with technological complexity.