Computational thinking (CT) plays a vital role in the fields of science, technology, engineering and mathematics (STEM). However, whether students' learning attitude towards STEM is related to their CT skills remains unknown. Two studies were conducted to address this knowledge gap. In Study 1, we validated a newly developed STEM learning attitude scale among a sample of Chinese primary school students (N = 489). Exploratory and confirmatory factor analysis results revealed that the scale which consisted of three factors (mathematics, science and information technology) could sufficiently measure primary school students' STEM learning attitude in the current sample. In Study 2, we explored the association between students' STEM learning attitude and their CT skills. Evidence revealed that learning attitude towards STEM significantly predicted CT skills. We also found that girls had a more positive learning attitude towards STEM than boys, and the fourth grade might be the key period for the development of CT skills. Implications for promoting primary school students' STEM learning and CT skills were also discussed.