The numbers of accumulated couples and their extra births are major concerns after im- plementing the universal two-child policy.Using data from the 2014 national population sampling sur- vey,this paper,employing a population group-component calculation and projection method,provides estimates of the size of extra births that would be influenced by the two-child policy after computing the amount of accumulated couples in 2016.The results show that the number of target population under the two-child policy would be at around 91 million in 2016 among which women at age 40 and above account for 49. 6% .Under medium fertility scenario,the size of extra births would reach around 17 mil- lion in 2017-2021 with an annual average number of 1.6-4. 7 million.Although the number of accu- mulated couples subject to the two-child policy is large,the size of their extra births would be relatively small,implying that China would have a smooth transition to the two-child policy.