Background:
In the same year 2015, PISA (The Programme for International Student Assessment) and TIMSS (Trends in International Mathematics and Science Study) are coming up to us together.PISA and TIMSS, which clock is more accurate to indicate national S&T (science & technology) competitiveness?

Material and methods:
Number of S & T journal articles (per million people) is used as a measure to represent the national S&T competitiveness. Average IQ of the population, research and development (R&D) expenditure (% of GDP) and number of R&D researchers and technicians which affect the national competitiveness in S&T were also investigated.

Results:
the study shows that PISA science scores would more significantly predict competence in S & T than TIMSS. Moreover, the study also shows a strong link between competence in S & T and IQ, R&D expenditure (% of GDP) or number of R&D researchers and technicians.

Conclusions:
The findings from this paper indicate that higher quality of human capital and more R&D inputs are the two magic weapons to national competence in S&T, especially higher quality of human capital.