During the rule of the pro-unification KMT, inviting tech experts and business professionals from Mainland China was not all that rampant. Quite the contrary, the DPP, after having held a hard stance against cross-strait exchanges, effected a policy reform concerning the recruitment of Mainland Chinese technology and business professionals following its role as the ruling party in 2000. Among the three possible explanations for the policy change in immigration, i.e. the national interest model, interest group model, and institutionalism model, this paper found that the national interest model could better explain the policymaking process, when examined, than the interest group model. Still, the institutionalism model, which focuses on the liberal paradox, the perception factors, and the human side of migrants, by and large affect and influence decision makers. Only by combining the national interest model and the institutionalism model could we fully understand the nature and basics of the dynamics of policy process in the opening up of recruiting mainland technology and business professionals to Taiwan.