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Bit-decomposition, which is proposed by Damg̊ard et al., is a powerful tool for multi-party computation (MPC). Given a sharing of secret x, it allows the parties to compute the sharings of the bits of x in constant rounds. With the help of bit-decomposition, constant-rounds protocols for various MPC problems can be constructed. However, bit-decomposition is relatively expensive, so constructing protocols for MPC problems without relying on bit-decomposition is a meaningful work. In multi-party computation, it remains an open problem whether the modulo reduction problem can be solved in constant rounds without bit-decomposition. In this paper, we propose a protocol for (public) modulo reduction without relying on bit-decomposition. This protocol achieves constant round complexity and linear communication com-plexity. Moreover, we show a generalized bit-decomposition protocol which can, in constant rounds, convert the sharing of secret x into the sharings of the digits of x, along with the sharings of the bits of every digit. The digits can be base-m for any m ≥ 2. Obviously, when m is a power of 2, this generalized protocol is just the original bit-decomposition protocol