Abstract. We consider the set K(n, c, x dy − y dx) of codimension one holomorphic foliations on P n , n ≥ 3, with Chern class c, and with a compact, connected Kupka set of radial transversal type. We will prove that foliations in this set, have a rational first integral and define an irreducible component of the space of foliations.0.1. Introduction. Let n ≥ 3 and c ≥ 2 be natural numbers. Consider a differential 1-form in C n+1 ω = a 0 dz 0 + · · · + a n dz n , ∈ where a j are homogeneous polynomials of degree c − 1 in variables z 0 , . . . , z n with complex coefficients. Let us assume that z 0 a 0 + · · · + z n a n = 0 so that ω descends to the complex projective space P n and defines a global section of the twisted sheaf of 1-forms Ω 1 P n (c). For a K-vector space V , we denote PV = V −{0}/K * the projective space of linear subspaces of V and π : V − {0} → PV the quotient map.Consider the projective space PH 0 (P n , Ω 1 (c)) and the subset F(n, c) := π { ω ∈ H 0 (P n , Ω 1 P n (c)) − 0 | ω ∧ dω = 0 } parameterizing 1-forms ω such that they satisfy the Frobenius integrability condition. This is the space of Chern class c foliations of codimension one on P n . It is an algebraic subset defined by quadratic equations, and has several irreducible components. For instance, let us recall (see [CL96], [GML91]) the following families of irreducible components:The rational components R n (a, b) ⊂ F(n, c) consisting of integrable 1-forms of the typewhere c = a + b is a partition with a, b natural numbers, p, q are the unique coprime numbers such that pa = qb and f, g are homogeneous polynomials of respective degree a, b.1991 Mathematics Subject Classification. 58A17, 32G99.