Crosslinkable poly (arylene ether nitrile)/hollow glass microsphere (PEN/HGM) composites with relative low dielectric permittivity and high thermal stability were prepared by a solution mixing and thermal compression method. For achieving this purpose, HGM were tight embedded in network, which were formed by crosslinking reaction of PEN end-capped with phthalonitrile. Compared to pure PEN, the dielectric constant of the resulting composite with 15 wt% of HGM reduced from 4.1 to 2.7 at 100 kHz, and the dielectric loss decreased from 2.0 9 10 -2 to 0.8 9 10 -2 at 100 kHz. Furthermore, the as-prepared composites showed significant enhancement in glass transition temperature (increased by 64°C) and onset thermal degradation temperature (increased by 41°C). Therefore, such composites were expected to find their applications area such as integrated circuit where needs low dielectric constant, low dielectric loss and high thermal stability.