Massive binary in this paper is the kind of binary, whose spectral type is earlierthan B5. Research on massive binary plays an important role in the mass and angular momentum transfer or loss between the components, and the evolution of binary. This paper does some statistics and analysis on the massive binary, some massive binaries are observed and analyzed. The results are obtained as follows: 1.It is discovered that the period of the O type binary LY Aur is increasing continuously at a rate of dP/dt =3.02 × 10−7days/year and a cyclic oscillation with a period of 13.1 years. The long-term period increase can be explained by the mass transfer from the less massive component to the more one, which indicates that the system is undergoing a Case A slow mass-transfer stage on the nuclear time scale of the secondary. The periodic change may be due to the light-travel time effect of the third component and the lowest mass of the third body is computed to be 4.02Msun. 2.Based on the O−C analysis of the B-type massive contact binary RZ Pyx, we find a cyclic period change of 46.2 years superimposed on a long-term increasing. The long-term increasing of orbital period is caused by the mass transfer from the secondary to the primary and the mass loss from the primary by the stellar wind. It possible makes RZ Pyx evolve to the direction of more shallower contact degree and the contact may be broken finally. The cyclic change of orbital period may be caused by the light-travel time effect of the third body, and this component may be a cool star with a mass of 0.3Msun . 3.It is found the orbital period of B-type semi-detached binary AI Cru has a long-term increasing, which indicates that the system is undergoing a Case A slow mass-transfer stage on the nuclear time scale of the secondary. The mass transfer from the secondary to the primary and the mass loss from the primary is the reason why the period is increasing. Analysis on the photoelectric and CCD data displays a cyclic change, and can be explained by the light-travel time effect of the third body with a lowest mass of 0.2Msun .
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