Heat capacities of halomethanes CBrCl3 and CBr2Cl2 were measured with an adiabatic calorimeter in the temperature range between 6 and 305 K. CBrCl3 and CBr2Cl2 crystallized into plastically crystalline phases at 267.9 and 294.4 K with entropy changes of 7.59 and 7.89 J K-1 mol(-1), and then into normal crystalline phases at 238.19 and 258.8 K with entropy changes of 19.40 and 21.06 J K-1 mol(-1), respectively. In CBrCl3, an extra transition between plastic phases was found at 259.34 K with a small entropy change of 2.03 J K-1 mol(-1). A glass transition owing to the freezing of the molecular motions probably associated with the exchange of positions between Cl and Br atoms was found at about 90 K for both substances.