We compute the partition function of the Potts model with arbitrary values of q and temperature on some strip lattices. We consider strips of width Ly = 2, for three different lattices: square, diced and 'shortest-path' (to be defined in the text). We also get the exact solution for strips of the Kagome lattice for widths Ly = 2, 3, 4, 5.As further examples we consider two lattices with different type of regular symmetry: a strip with alternating layers of width Ly = 3 and Ly = m + 2, and a strip with variable width. Finally we make some remarks on the Fisher zeros for the Kagome lattice and their large q-limit.where the temperature variable v = e K − 1 has been introduced with K ≡ βJ. For the ferromagnetic case (J > 0) one has 0 ≤ v ≤ ∞ corresponding to the temperature interval ∞ ≥ T ≥ 0; for the antiferromagnetic Potts (J < 0) the interval −1 ≤ v ≤ 0 corresponds to 0 ≤ T ≤ ∞. It can be shown directly from (1.1) that the partition function admits also the following polynomial (Fortuin-Kasteleyn) representation [9,10],1.2) * alvarez AT cecs.cl † canfora AT cecs.cl ‡ sreyes AT fis.puc.cl arXiv:0912.4705v4 [cond-mat.stat-mech] 7 May 2012where G is a graph with the same vertex set V of G and an edge set E ⊆ E, with E being the edge set of G; k(G ) and e(G ) are respectively the number of connected components and the number of vertices of G . It is important to notice that using (1.2) one can extend q and v from their physical values (q ∈ Z + , v ∈ [−1, +∞)) to the whole complex plane.Unlike the case of the Ising model (q = 2), solved by Onsager [11], the exact solution for the Potts model in any infinite two dimensional lattice is still not available. Nevertheless, thanks to universality, the critical behavior of the ferromagnetic Potts model is fairly well understood. On the other hand, the antiferromagnetic Potts depends on the structural properties of the lattice and its critical properties can vary strongly from case to case. Thus, the search for tools to obtain analytical information on the free energy of the Potts model on generic lattices is a very important task.An approach that has proven fruitful in recent years is to solve the simpler problem of calculating the partition function for periodic strips of finite width (L y ) and arbitrary length (L x ). Previous work along these lines has relied basically on a transfer matrix method [12,13,14,15,16] to obtain exact results at arbitrary temperatures for strips of widths going up to L y = 7 (honeycomb lattice with free boundary conditions) [17]. Such efforts have produced detailed studies for the square, triangular, and honeycomb lattices [18,14,15,16,19,20,17,21].In many cases it is useful to exploit the recursive structure which is present in lattices of physical interest. Even when the analytic solution is not available, using a simple ansatz which respects the recursive symmetry one can get an excellent agreement with the numerical data [22,23,24,25]. Motivated by these facts we develop a method that permits the calculation of the exact partition function ...