In this paper we derive the power loading method for Band Aggregation (BA) Single Carrier-Frequency Division Multiple Access (SC-FDMA) with Zero-Forcing Frequency Domain Equalizer (ZF-FDE). In previous research [6], they derive the optimal power allocation for SC-FDMA with single band, however, this result cannot directly be extended to multiple bands. Thus, we proposed sub-optimal the two stages power loading scheme for SC-FDMA with ZF-FDE in multiple bands. First, we optimize the total powers of each band and then powers of each sub-carrier are optimized by using optimal power in the first step. Simulation results show that the proposed power control is particularly effective in improving the achievable data rate at low Signal to Noise Ratio (SNR).