Abstract Temperature dependence of magnetic susceptibility is reported for polycrystalline samples of La 2CuO 4 prepared under several conditions to reduce excess oxygen. The sample calcined at 1050°C in flowing argon and quenched shows a sharp peak at a Néel temperature T N of 302K. The sample calcined at 1050°C in flowing oxygen and quenched shows T N of 292K, which increases up to 304K after deoxygenation at 500°C in flowing argon. These results show that further deoxygenation in flowing argon is necessary in order to reduce excess oxygen completely. It should be noted that the sample with T N of 292K shows another peak at 64K. This peak shifts to 20K after annealing at 1000°C in flowing oxygen, indicating that the low temperature peak can not be related to existence of bulk oxygen. Neither existence of impurity phases nor distribution of T N can explain appearance of the low temperature peaks. These results strongly suggest existence of some magnetic transition in La 2CuO 4 with fairly slight amounts of excess oxygen.