Abstract: To cope with the problem of scan chain distribution of system-on-chip (SoC) IP core, this paper proposes quantum ant colony algorithm as an optimization scheme, which can effectively solve the problems that the results easily fall into local optimal solution, and quickly find the best distribution of scan chain, thereby shortening the longest scan chain, reducing test time for a single IP core. Typical IP core of ITC'02 Test benchmarks is adopted, and the experimental results show that the quantum ant colony optimization algorithm can effectively and fastly solve the problem of the scheme.