The effects of testosterone administration on the Iocalization of the androgen receptor and on the activity of nuclear phosphorylation were investigated in female mouse submandibular gland. Administration of testosterone (500μg/100 g body weight) to female mice caused translocation of androgen receptor from the cytosol to the nucleus within 3hrs. Approximately 80% of the nuclear receptor bound to the active chrornatin which was prepared from the nucleus by micrococcal nuclease digestion. Incorporation of ³² P from [γ-³²P] ATP into the nucleus was enhanced 3hrs after testosterone administration and then the enhanced incorporation returned to acontrol level in 6~9hrs. Such a phosphorylation activity was found in the active chromatin and asimilar effect of testosterone administration was observed on ³²P incorporation. Nonhistone proteins, which were extracted from the ³²P-labeled nucleus with 0.35 M NaCl, were mainly phosphorylated. These results indicate that mouse submandibular gland contains protein kinases which are activated by the nuclear androgen receptor, and that the kinases seem to be lnvolved in the transcription activation modulated by the androgen receptor.