ABSTRAKPenelitian ini bertujuan untuk mengetahui karakteristik ukuran dimensi tubuh hasil persilangan resiprokal ayam petelur dan bangkok fase starter. Materi yang digunakan dalam penelitian yaitu 120 ekor ayam yang terdiri atas 60 ekor ayam PB (jantan petelur x betina bangkok) dan 60 ekor ayam BP (jantan bangkok x betina petelur). Data pengukuran ditabulasi, dianalisis secara deskriptif dan menggunakan Uji T. Parameter yang diamati adalah bobot badan, panjang badan, panjang rentang sayap, pertumbuhan dan lingkar dada. Hasil penelitian diperoleh secara umum pertambahan bobot badan, panjang badan, panjang shank, panjang rentang sayap, lingkar dada dan pertumbuhan ayam BP lebih besar dibandingkan ayam PB.Kata Kunci: ayam bangkok,.ayam petelur, resiprokal, ukuran tubuhABSTRACTThis study aimed to determine the characteristics of chicken body sizes resulted from reciprocal crossbreeding of laying hens and bangkok chicken on starter phase. The materials were 120 chickens including 60 chickens PB (male layer chicken x female bangkok chicken) and 60 BP chickens (bangkok rooster x female layer chicken). Measurement data were tabulated, analyzed descriptively and T-Student. The parameters observed were body weight, body weight, body length, chest circumference, beak length, and wing pan length. The result showed that generally, body weight, body length, shank length, length of wing span, chest circumference and body weight gain of BP (bangkok rooster x female layer chicken) were greater than PB (layer chicken rooster x bangkok female).Keywords: bangkok chicken, body size, laying chicken, reciprocal