<p>A bicycle lock includes a first part and (1) a second part (2) located close to a bicycle wheel by two bolts (4, 5) with two respective protection members (13, 25) connected to the first part and the second part respectively. The protection members cover the heads of the bolts so that an unauthorized person cannot access the bolts to detach the bicycle lock from the bicycle. A lock rod (14) is connected to the first part which is pivotable about the bolt corresponding thereto so as to be inserted into the second part to lock the wheel.</p>