This study investigated the relationship between formative assessment and reading achievement in Hong Kong, a Confucian Heritage Culture (CHC) society. 4,837 Hong Kong students were surveyed in a nine-item questionnaire that was used as indicator variable of formative assessment strategies. The study used multi-group structural equation modelling (MG-SEM) to examine the effects of formative assessment strategies on reading achievement across low-, medium-, and high-achievers controlling for gender and social economic status (SES) effects. The result showed that after controlling for SES and gender effects, there was significant effect of formative assessment strategies with low- and medium-reading achievers but not with high-reading achievers. Implications are drawn to inform formative assessment research and practice relevant to students' reading achievement in CHC societies and other educational contexts.