Kacang panjang polong ungu mengandung antosianin yang bermanfaat bagi tubuh. Selain memiliki kandungan gizi, kacang panjang polong ungu harus dijamin kebenaran varietasnya. Pengujian kebenaran dan kemurnian diperlukan untuk memperbarui mutu benih dalam rangka pelepasan varietas. Tujuan pelaksanaan penelitian ini ialah untuk menguji kebenaran dan mengetahui tingkat kemurnian masing-masing enam varietas kacang panjang polong ungu. Penelitian ini berlokasi di Lahan Percobaan Jatimulyo Fakultas Pertanian, Universitas Brawijaya di Desa Jatimulyo, Kecamatan Lowokwaru, Malang, Jawa Timur. Penelitian dilaksanakan pada bulan Maret-Juni 2019. Bahan yang digunakan meliputi enam varietas kacang panjang polong ungu, yaitu BU 1, BU 2, BU 3, BU 4, BU 5 dan BU 6. Penelitian dilakukan dengan pembuktian secara visual, yaitu membandingkan keragaan tanaman dengan deskripsinya. Hasil penelitian membuktikan bahwa, pada karakter kualitatif keenam varietas kacang panjang ungu telah sesuai dengan deskripsi PPVT. Pada karakter kuantitatif didapatkan nilai KK pada keenam varietas dengan kisaran rendah hingga sedang. Kata Kunci: Kacang Panjang, PPVT, Tingkat Kemurnian, Uji Kebenaran. ABSTRACT Purple yardlong bean contain anthocyanins which are beneficial to the body. In addition to high nutrtion, purple yardlong bean must be guaranteed validation of a varieties. Validity test and purity still need to be done to renew seed quality in order to release plant varieties. The purpose of this research is to test the validity and to determine the purity level of six varieties purple yardlong bean. This research was located at Experimental Field of the Faculty of Agriculture, Universitas Brawijaya in Jatimulyo Village, Lowokwaru District, Malang, East Java. The research was conducted from March to June 2019. The materials used included six varieties purple yardlong beans, BU 1, BU 2, BU 3, BU 4, BU 5 dan BU 6. The research was conducted by visual verification, which compares the diversity of plants with their description. The result showed, in qualitative character of the six varieties purple yardlong bean in accordance with the PPVT description. In quantitative character, KK values of six varieties has a value KK low to medium.