A bottle cap depressable to eject contents of the bottle has a depressing outlet member, a connecting member and a securing member. The securing member has an upper and a lower securing end portions each having several securing teeth. The upper end securing teeth have upwards-aimed sloped surfaces while the lower end securing teeth have downwards-aimed sloped surfaces. The upper and the lower securing end portions are inserted into the depressing outlet member, and a straw combination respectively with the securing teeth of the upper and the lower end portion securely engaging the inner circumference of the depressing outlet member and that of the straw combination respectively. Thus, the depressing outlet member is securely connected to the straw combination, preventing the bottle from separating from the outlet member and falling down to the ground when a user lifts the bottle from the outlet member.