A heat dissipating device includes a base and at least one spring fastener. The spring fastener comprises a fastener and a spring sleeved on the fastener. A through hole allowing the spring fastener to pass through is formed on the base. A buckle is arranged in the through hole or nearby the through hole on the base and is integrated with the base. The buckle clips at least one spring ring of the spring between the base and the buckle. A ring protuberance is projected on the outer surface of the spring fastener near the top end. A groove is formed by the space between the top end of the spring fastener and the ring protuberance. The top ring of the spring is sleeved in the groove. Compared with the prior art, the invention uses the buckle on the base to replace a retaining ring, reduces cost for retaining ring assembly and materials, and eliminates risk of short-circuit of circuit board caused by retaining ring falling off.