The thermal expansion and low-temperature specific heat measurements for Y6(Mn1-xFex)23 compounds have been carried out in order to discuss the relationship between the thermal expansion anomaly and the spin fluctuations. The thermal expansion coefficient a significantly increases above the Curie temperature TC. This behaviour, the so-called anti-invar characteristic, is attributed to a remarkable increase of the amplitude of spin fluctuations in paramagnetic temperature regions. The anti-invar characteristic becomes weaker with increasing x. The temperature dependence of the thermal expansion coefficient of the magnetic term αmag is convex upward in the paramagnetic temperature range, which is explained within the framework of spin fluctuations.