New photoelectric photometry is presented for the β CMa type variables β Cru, αLup and τ1 Lup. frequency analysis of the βCru data and of earlier published photometry and velocities shows that its period is 0d.19120, rather than the periods suggested previously of 0d.16 or 0d.24. The data for τ1 Lup are the largest photometric data set for this star and the period determined by Pagel (1956) from radial velocity observations is confirmed. α Lup is found to have a small variation of its β index (of 0.0027 mag) during the 0d.26 period of the light variation, suggesting a temperature change of about 1000°K during the cycle. One β CMa variable, HDE 32633, has been found in the young cluster NGC 6231. The frequency spectrum of the data changed significantly from 1972 to 1973, but its period is in the region of 0d .1, which is one of the shortest known for a β CMa variable.