Аннотация:We found that the known spectroscopic binary and variable BU CMi = HD65241 (V=6.4-6.7 mag, Sp~= A0 V) is a quadruple doubly eclipsing 2+2 system. Both eclipsing binaries are detached systems moving in an eccentric orbits: pair "A" with the period Pa = 2.94 days(e=0.20) and pair "B" with the period Pb = 3.26 days (e=0.22). All four components have nearly equal sizes, temperatures and masses in the range M = 3.1--3.4 M⊙ and A0 spectra. We derived the mutual orbit of both pairs around the system barycenter with a period of 6.54 years and eccentricity e = 0.71. We detected in pairs "A" and "B" the fast apsidal motion with the periods Ua = 25.0 years and Ub = 25.2 years. The orbit of each pair shows small nutation-like oscillations in periastron longitude. The age of the system estimated as 200 mln. years. The photometric parallax calculated from the found parameters coincides perfectly with the GAIA DR2 π=0.00407"±0.00006".
