Potential roles of RNA N6-methyladenosine (mA) modification in tumour microenvironment (TME) cell infiltration has been demonstrated in recent studies. Nonetheless, the mechanism of its regulation remains unknown and immunotherapy has been marginal in prostate cancer. We demonstrated the expression of different mA regulators within prostate cancer related to genetic variation, alternative splicing (AS), tumour mutational burden (TMB) and TME. Unsupervised clustering and risk prediction model constructed by 24 mA regulators could predict scores of TME and prostate cancer patients prognosis. T cells CD8 was the intersection of immune cells which are related to multiple biological processes, and the fraction of T cells CD8 strongly correlates with immune associated gene sets. mA methylation modification and immune cells infiltration played a nonnegligible role in prostate cancer. Our study represents a step towards personalized immunotherapy for prostate cancer patients.