Abstract: The father of Meiji constitution Ito Hirobumi's party politics view has experienced a process of transformation from the original concept of "evil party" to the final "party tool theory". This change was based on the Japanese parties' dynamic politics activities after the Meiji constitution was promulgated. Along with the change of party politics view, Ito took different measures on the constitutional political practices on the parties. At the beginning he avoided particularly talking about political parties in the constitutional text and suppressing the political parties, and compromised afterwards to all kinds of parties due to the political need, and created Seiyukai finally. The transition of his view of party politics and practices has a great influence on modern Japanese parties' political activities.

Key words: Ito Hirobumi, party polities, Meiji constitution, Seiyukai