https://github.com/facebook/react/issues/3926#issuecomment-240136007

issue3926.js

import React from 'react';
import ReactDOM from 'react-dom';

class Issue3926 extends React.Component {
  constructor() {
    super();
    this.handleChange = this.handleChange.bind(this);
    this.handleComposition = this.handleComposition.bind(this);
    this.onComposition = false;
    this.state = {
      value: ''
    };
  }

  handleChange(e) {
    if (!this.onComposition) {
      console.log(e.type, e.target.value);
      this.setState({
        value: e.target.value
      });
    }
  }

  handleComposition(e) {
    console.log(e.type);
    if (e.type === 'compositionend') {
      this.onComposition = false;
    } else {
      this.onComposition = true;
    }
  }

  render() {
    return (
      <div>
        <input
          type="text"
          onCompositionStart={this.handleComposition}
          onCompositionUpdate={this.handleComposition}
          onCompositionEnd={this.handleComposition}
          onChange={this.handleChange}
        />
      </div>
    );
  }
}

ReactDOM.render(<Issue3926 />, document.getElementById('app'));