We have demonstrated a robust and easy frequency stabilization method for Ti:sapphire laser, using Doppler-broadened Zeeman spectrum. In this method, only very weak laser output power (<1 mW) is required, and the experimental setup is relatively simple. A long-time frequency stability of less than 1 MHz/h is achieved. In addition, the stability is not affected directly by the laser output power fluctuation and the frequency locking point could be set arbitrarily in the Doppler-broadened spectral range.