Based on the generalized uncertainty principle (GUP), the critical temperature and the Helmholtz free energy of Bose-Einstein condensation (BEC) in the relativistic ideal Bose gas are investigated. At the non-relativistic limit and the ultra-relativistic limit, we calculate the analytical form of the shifts of the critical temperature and the Helmholtz free energy caused by weak quantum gravitational effects. The exact numerical results of these shifts are obtained. Quantum gravity effects lift the critical temperature of BEC. By measuring the shift of the critical temperature, we can constrain the deformation parameter β0. Furthermore, at lower densities, omitting quantum gravitational effects may lead to a metastable state while at sufficiently high densities, quantum gravitational effects tend to make BEC unstable. Using the numerical methods, the stable-unstable transition temperature is found.In the absence of a full theory of quantum gravity, effective models are useful tools to gain some experimental signatures from quantum theory of gravity. This is so-called quantum-gravity phenomenology or Planckscale phenomenology [1,2]. Most studies focused on the gamma-ray astrophysics [3][4][5][6], fundamental particle processes [7][8][9][10], neutrino physics [11,12] and the laser-interference of gravity waves [13][14][15][16][17], where particles exist in the ultra-relativistic regime. It is also possible to test quantum gravity effects using cold or slow atoms, where particles exist in the non-relativistic regime [18][19][20][21]. In [20][21][22][23][24], quantum gravity effects of non-traped and harmonically trapped Bose-Einstein condensates are examined respectively using the deformed non-relativistic free-particle energy-momentum dispersion relation. Quantum gravity effects cause an explicit shift in the condensation temperature, and then ultraprecise measurements of the condensation temperature make it possible to upper-bound the deformation parameter. Therefore, BEC opens a new road to quantumgravity phenomenology.The effective quantum gravity models used in the above are modified dispersion relations (MDR). Quantum gravity theories also predict that gravity itself leads to an effective cutoff in the ultraviolet, i.e., a minimal observable length [25,26]. Some realizations of the minimal length from various scenarios are proposed. One of the most important models is the generalized uncertainty principle (GUP), derived from the generalized commutation relationwhere β = β 0 l 2 p / 2 = β 0 /c 2 M 2 p with the Planck mass M p = c/G and the Planck length l p = G /c 3 . β 0 is a dimensionless parameter. And then, we can get the * Corresponding author. zhangxm@uestc.edu.cn † rectaflex@gmail.com familiar form of GUPthis in turn gives the minimum measurable lengthIn this letter, based on the generalized uncertainty principle (GUP), we are going to investigate the effects of the minimal length on Bose-Einstein condensation in the relativistic ideal Bose gas. Instead of considering thermodynamical functions of the re...