For a complete minimal surface in the Euclidean 3-space, the so-called
flux vector corresponds to each end. The flux vectors are balanced, i
.e., the sum of those over all ends are zero. Consider the following i
nverse problem: For each balanced n vectors, find an n-end catenoid wh
ich attains the given vectors as flux. Here, an n-end catenoid is a co
mplete minimal surface of genus 0 with ends asymptotic to the catenoid
s. In this paper, the problem is reduced to solving algebraic equation
. Using this reduction, it is shown that, when n = 4, the inverse prob
lem for the 4-end catenoids has solutions for almost all balanced 4 ve
ctors. Further obstructions for n-end catenoids with parallel flux vec
tors are also discussed.