The influences of stabilizers on beta- and beta "-Al2O3 phase formations in Li2O(MgO)-Na2O-Al2O3 systems were investigated. When stabilized with 4MgCO(3). Mg(OH)(2). 5H(2)O, most of the beta "-Al2O3 phase formed below 1200 degrees C and further beta- to beta "-Al2O3 transformation with an increase of temperature was not observed. On the other hand, when stabilized with Li2CO3, beta "-Al2O3 formation occurred by two steps. First, beta "-Al2O3 was partly formed below 1200 degrees C, and, second, noticeable transformation from beta-Al2O3 to beta "-Al2O3 occurred at higher temperature ranges. It was shown that transient eutectic liquid in the Li2O-Na2O-Al2O3 system promoted the beta- to beta "-Al2O3 transformation at higher temperatures. Uniform distribution of both Mg2+ and Li+ stabilizing ions enhanced beta "-Al2O3 formation at low temperatures. In the Li-stabilized systems, however, homogeneous distribution of Li+ ions hindered both the formation of transient eutectic liquid and the second beta- to beta "-Al2O3 phase transformation at high temperatures.